func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 200000 + 10;   int n;   long long x[N], y[N];   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) {       scanf( %lld%lld , &x[i], &y[i]);     }     while (1) {       vector<int> r;       for (int i = 1; i <= n; i++) {         if ((x[i] + y[i]) % 2 == 0) r.push_back(i);       }       if (r.size() == 0 || r.size() == n) {         for (int i = 1; i <= n; i++) {           long long tx = x[i];           long long ty = y[i];           x[i] = tx - ty;           y[i] = tx + ty;         }         if (x[1] % 2 != 0) {           for (int i = 1; i <= n; i++) {             x[i]++, y[i]++;             x[i] /= 2, y[i] /= 2;           }         }         while (1) {           bool ok = 1;           for (int i = 1; i <= n; i++) {             if (x[i] % 2 || y[i] % 2) ok = 0;           }           if (ok) {             for (int i = 1; i <= n; i++) {               x[i] /= 2, y[i] /= 2;             }           } else {             break;           }         }         continue;       }       printf( %d n , r.size());       for (auto x : r) {         printf( %d  , x);       }       return 0;     }   }   