func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MX = 1e5 + 9;   int n, a[MX], sum;   void dp(int x, int y, int sum1, int sum2) {     if ((x | y) == (1 << n) - 1) {       if (!x || !y) return;       if (sum1 != sum2) {         cout << __builtin_popcount(x) << endl;         for (int i = 0; i < n; i++) {           if (x & (1 << i)) cout << i + 1 <<    ;         }         exit(0);       }     }     for (int i = 0; i < n; i++) {       if ((x & (1 << i)) || (y & (1 << i))) continue;       dp(x | (1 << i), y, sum1 + a[i], sum2);       dp(x, y | (1 << i), sum1, a[i] + sum2);     }   }   int main() {     cin >> n;     for (int i = 0; i < n; i++) {       cin >> a[i];       sum += a[i];     }     dp(0, 0, 0, 0);     puts( -1 );   }   