func_code_string: #include <bits/stdc++.h>   using namespace std;   int x[1000 + 1], y[1000 + 1];   void solve() {     int n;     cin >> n;     for (int i = 0; i < n + 1; i++) cin >> x[i] >> y[i];     int res = 0;     for (int i = 1; i < n; i++) {       double X = x[i], Y = y[i];       int cnt = 0;       if (x[i - 1] == x[i]) {         if (y[i] > y[i - 1])           Y += 0.2;         else           Y -= 0.2;         for (int j = 0; j < n; j++)           if (x[j] == x[j + 1] && x[j] < x[i] && min(y[j], y[j + 1]) < Y &&               Y < max(y[j], y[j + 1]))             cnt++;         if (cnt % 2 == 1) res++;       } else {         if (x[i] > x[i - 1])           X += 0.2;         else           X -= 0.2;         for (int j = 0; j < n; j++)           if (y[j] == y[j + 1] && y[j] < y[i] && min(x[j], x[j + 1]) < X &&               X < max(x[j], x[j + 1]))             cnt++;         if (cnt % 2 == 1) res++;       }     }     cout << res;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     solve();     return 0;   }   