diff --git a/C++ProjectTemplate b/C++ProjectTemplate
index c1aa29d..780dadb 100755
Binary files a/C++ProjectTemplate and b/C++ProjectTemplate differ
diff --git a/input b/input
new file mode 100644
index 0000000..fe5a85e
--- /dev/null
+++ b/input
@@ -0,0 +1,33 @@
+Sensor at x=1555825, y=18926: closest beacon is at x=1498426, y=-85030
+Sensor at x=697941, y=3552290: closest beacon is at x=595451, y=3788543
+Sensor at x=3997971, y=2461001: closest beacon is at x=3951198, y=2418718
+Sensor at x=3818312, y=282332: closest beacon is at x=4823751, y=1061753
+Sensor at x=2874142, y=3053631: closest beacon is at x=3074353, y=3516891
+Sensor at x=1704479, y=2132468: closest beacon is at x=1749091, y=2000000
+Sensor at x=3904910, y=2080560: closest beacon is at x=3951198, y=2418718
+Sensor at x=657061, y=3898803: closest beacon is at x=595451, y=3788543
+Sensor at x=3084398, y=3751092: closest beacon is at x=3074353, y=3516891
+Sensor at x=2582061, y=972407: closest beacon is at x=1749091, y=2000000
+Sensor at x=2886721, y=3971936: closest beacon is at x=3074353, y=3516891
+Sensor at x=303399, y=548513: closest beacon is at x=-1010425, y=986825
+Sensor at x=3426950, y=2290126: closest beacon is at x=3951198, y=2418718
+Sensor at x=3132858, y=3592272: closest beacon is at x=3074353, y=3516891
+Sensor at x=3773724, y=3751243: closest beacon is at x=3568452, y=3274758
+Sensor at x=3987212, y=2416515: closest beacon is at x=3951198, y=2418718
+Sensor at x=61559, y=3806326: closest beacon is at x=595451, y=3788543
+Sensor at x=2693503, y=2291389: closest beacon is at x=2269881, y=2661753
+Sensor at x=3953437, y=2669220: closest beacon is at x=3951198, y=2418718
+Sensor at x=763035, y=3997568: closest beacon is at x=595451, y=3788543
+Sensor at x=3999814, y=2370103: closest beacon is at x=3951198, y=2418718
+Sensor at x=1290383, y=1696257: closest beacon is at x=1749091, y=2000000
+Sensor at x=3505508, y=2805537: closest beacon is at x=3568452, y=3274758
+Sensor at x=3276207, y=3323122: closest beacon is at x=3568452, y=3274758
+Sensor at x=2244609, y=3517499: closest beacon is at x=3074353, y=3516891
+Sensor at x=1370860, y=3436382: closest beacon is at x=595451, y=3788543
+Sensor at x=3831063, y=3042662: closest beacon is at x=3568452, y=3274758
+Sensor at x=551202, y=3971545: closest beacon is at x=595451, y=3788543
+Sensor at x=336629, y=2519780: closest beacon is at x=595451, y=3788543
+Sensor at x=2033602, y=2882628: closest beacon is at x=2269881, y=2661753
+Sensor at x=3939808, y=2478271: closest beacon is at x=3951198, y=2418718
+Sensor at x=1958708, y=2370822: closest beacon is at x=1749091, y=2000000
+Sensor at x=3039958, y=3574483: closest beacon is at x=3074353, y=3516891
diff --git a/main.cpp b/main.cpp
index 8ab7e53..35f0099 100644
--- a/main.cpp
+++ b/main.cpp
@@ -4,86 +4,90 @@
 
 using namespace olc;
 
-class Example : public olc::PixelGameEngine
-{
-public:
-	Example()
-	{
-		sAppName = "Example";
-	}
-
-public:
-    bool RayVsRect(const vf2d ray_origin, const vf2d ray_dir, const olc::utils::geom2d::rect<float> target, vf2d&contact_point, vf2d&contact_normal, float&t_hit_near){
-
-        contact_normal = { 0, 0 };
-        contact_point = { 0, 0 };
-
-        vf2d t_near = {(target.pos.x - ray_origin.x) / ray_dir.x, (target.pos.y - ray_origin.y) / ray_dir.y};
-        vf2d t_far = {(target.pos.x + target.size.x - ray_origin.x) / ray_dir.x, (target.pos.y + target.size.y - ray_origin.y) / ray_dir.y};
-
-        if (t_near.x > t_far.x) {float b; b = t_near.x; t_near.x = t_far.x; t_far.x = b;};
-        if (t_near.y > t_far.y) {float b; b = t_near.y; t_near.y = t_far.y; t_far.y = b;};
-
-        if (t_near.x > t_far.y || t_near.y > t_far.x) return false;
-
-        t_hit_near = fmax(t_near.x, t_near.y);
-        float t_hit_far = fmin(t_far.x, t_far.y);
-
-        if (t_hit_far < 0) return false;
-
-        contact_point.x = ray_origin.x + t_hit_near * ray_dir.x; 
-        contact_point.y = ray_origin.y + t_hit_near * ray_dir.y;
-
-        if (t_near.x > t_near.y)
-            if ( 1.0f / ray_dir.x < 0)
-                contact_normal = { 1, 0 };
-            else
-                contact_normal = { -1, 0};
-        else 
-        if ( t_near.x < t_near.y)
-            if ( 1.0f / ray_dir.y < 0)
-                contact_normal = { 0, 1 };
-            else
-                contact_normal = { 0, -1 };
-        
-        return true;
-
-        
-    }
-    vf2d originPoint={16,16};
-	bool OnUserCreate() override
-	{
-		// Called once at the start, so create things here
-		return true;
-	}
-
-	bool OnUserUpdate(float fElapsedTime) override
-	{
-        vf2d velocity={(GetKey(D).bHeld-GetKey(A).bHeld)*20*fElapsedTime,(GetKey(S).bHeld-GetKey(W).bHeld)*20*fElapsedTime};
-        vf2d contact_point;
-        vf2d contact_normal;
-        float t_hit_near;
-
-		Clear(Pixel(64,64,255));
-        if (!olc::utils::geom2d::overlaps(olc::utils::geom2d::circle<float>{originPoint+velocity,5},olc::utils::geom2d::rect<float>{{32,32},{64,32}})) {
-            originPoint+=velocity;
-            DrawCircle(originPoint,5);
-        } else {
-            DrawCircle(originPoint,5,RED);
-        }
-        DrawLine(originPoint,GetMousePos());
-
-        DrawRect({32,32},{64,32},RayVsRect(originPoint, GetMousePos()-originPoint, olc::utils::geom2d::rect<float>{{32,32},{64,32}},contact_point,contact_normal,t_hit_near)&&t_hit_near<1?YELLOW:WHITE);
-		return true;
-	}
+struct Sensor{
+    vi2d pos;
+    int radius;
 };
 
-
 int main()
 {
-	Example demo;
-	if (demo.Construct(128, 120, 8, 8))
-		demo.Start();
+	std::ifstream file("input");
+    std::vector<Sensor>sensors;
+    while (file.good()){
+        std::string line;
+        std::getline(file,line);
+        std::cout<<line<<std::endl;
+        int prevMarker=0;
+        int marker=line.find(' ',prevMarker);
+        vi2d sensorPos={-999,-999};
+        vi2d beaconPos={-999,-999};
+        if (line.length()>0){
+            while (prevMarker!=std::string::npos){
+                std::string word=line.substr(prevMarker,marker-prevMarker);
+                prevMarker=marker;
+                marker=line.find(' ',prevMarker+1);
+                if (word[1]=='x'){
+                    if (sensorPos.x==-999){
+                        sensorPos.x=std::atoi(word.substr(word.find('=')+1,word.find(',')-word.find('=')-1).c_str());
+                        std::cout<<"Sensor X: "<<sensorPos.x<<std::endl;
+                    } else {
+                        beaconPos.x=std::atoi(word.substr(word.find('=')+1,word.find(',')-word.find('=')-1).c_str());
+                        std::cout<<"Beacon X: "<<beaconPos.x<<std::endl;
+                    }
+                } else
+                if (word[1]=='y'){
+                    if (sensorPos.y==-999){
+                        sensorPos.y=std::atoi(word.substr(word.find('=')+1,word.find(',')-word.find('=')-1).c_str());
+                        std::cout<<"Sensor Y: "<<sensorPos.y<<std::endl;
+                    } else {
+                        beaconPos.y=std::atoi(word.substr(word.find('=')+1,word.find(',')-word.find('=')-1).c_str());
+                        std::cout<<"Beacon Y: "<<beaconPos.y<<std::endl;
+                    }
+                }
+            }
+            sensors.push_back({sensorPos,std::abs(beaconPos.x-sensorPos.x)+std::abs(beaconPos.y-sensorPos.y)});
+            std::cout<<"Sensor -> Beacon Radius: "<<sensors[sensors.size()-1].radius<<std::endl;
+            std::cout<<std::endl;
+        }
+    }
+    int targetY=2000000;
+    int sum=0;
+    std::vector<std::pair<int,int>>ranges;
+    for (Sensor s:sensors){
+        int distance=std::abs(s.pos.y-targetY);
+        if (distance<s.radius){
+            //In range.
+            std::cout<<"Sensor "<<s.pos<<" in range of Y "<<targetY<<" Radius: "<<s.radius<<std::endl;
+            int rangeSize=s.radius*2-distance*2+1;
+            std::cout<<"Leaves a range of "<<rangeSize<<std::endl;
+            int minX=(s.pos.x-rangeSize/2);
+            int maxX=(s.pos.x+rangeSize/2);
+            std::cout<<"Range is from "<<minX<<" ~ "<<maxX<<std::endl;
+            for (int i=0;i<ranges.size();i++){
+                if (ranges[i].first<=minX&&ranges[i].second>=maxX){
+                    maxX=minX-1;
+                    break;
+                }
+                if (ranges[i].first>minX&&ranges[i].second<maxX){
+                    sum-=ranges[i].second-ranges[i].first+1;
+                    std::cout<<"  --> Removed Range "<<ranges[i].first<<" ~ "<<ranges[i].second<<std::endl;
+                    ranges.erase(ranges.begin()+i--);
+                }
+                if (ranges[i].first<=maxX&&ranges[i].second>=maxX){
+                    maxX=ranges[i].first-1;
+                }
+                if (ranges[i].first<=minX&&ranges[i].second>=minX){
+                    minX=ranges[i].second+1;
+                }
+            }
+            if (maxX>=minX){
+                std::cout<<"  --> Range is truncated to "<<minX<<" ~ "<<maxX<<std::endl;
+                sum+=maxX-minX+1;
+                ranges.push_back({minX,maxX});
+            }
+        }
+    }
+    std::cout<<"Sum: "<<sum-1<<std::endl;
 
 	return 0;
 }
diff --git a/testinput b/testinput
new file mode 100644
index 0000000..652e631
--- /dev/null
+++ b/testinput
@@ -0,0 +1,14 @@
+Sensor at x=2, y=18: closest beacon is at x=-2, y=15
+Sensor at x=9, y=16: closest beacon is at x=10, y=16
+Sensor at x=13, y=2: closest beacon is at x=15, y=3
+Sensor at x=12, y=14: closest beacon is at x=10, y=16
+Sensor at x=10, y=20: closest beacon is at x=10, y=16
+Sensor at x=14, y=17: closest beacon is at x=10, y=16
+Sensor at x=8, y=7: closest beacon is at x=2, y=10
+Sensor at x=2, y=0: closest beacon is at x=2, y=10
+Sensor at x=0, y=11: closest beacon is at x=2, y=10
+Sensor at x=20, y=14: closest beacon is at x=25, y=17
+Sensor at x=17, y=20: closest beacon is at x=21, y=22
+Sensor at x=16, y=7: closest beacon is at x=15, y=3
+Sensor at x=14, y=3: closest beacon is at x=15, y=3
+Sensor at x=20, y=1: closest beacon is at x=15, y=3
\ No newline at end of file