func_code_string: #include <bits/stdc++.h>   using namespace std;   struct Point {     int x, y;     Point() {}     Point(int a, int b) {       x = a;       y = b;     }   };   double hypt(Point A, Point B) {     return sqrt((B.x - A.x) * (B.x - A.x) + (B.y - A.y) * (B.y - A.y));   }   int main() {     int k, n;     cin >> n >> k;     vector<Point> v(n);     for (int i = 0; i < n; i++) {       cin >> v[i].x >> v[i].y;     }     double ans = 0;     for (int i = 1; i < n; i++) {       ans += hypt(v[i], v[i - 1]);     }     ans *= k;     ans /= 50;     printf( %.10lf , ans);     return 0;   }   