func_code_string: #include <bits/stdc++.h>   using namespace std;   int main(int argc, char** argv) {     long long r, x1, y1, x2, y2;     while (cin >> r >> x1 >> y1 >> x2 >> y2) {       double dis = sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) + 0.0);       cout << ceil(dis / 2 / r) << endl;     }     return 0;   }   