func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, k;     cin >> n >> k;     int x, y, a, b;     double dis = 0;     cin >> x >> y;     a = x;     b = y;     n--;     while (n--) {       cin >> x >> y;       dis += (double)sqrt(pow(y - b, 2) + pow(x - a, 2));       a = x;       b = y;     }     dis = (dis / 50) * k;     printf( %.6f , dis);     return 0;   }   