#include <bits/stdc++.h>
using namespace std;
int n, a[10], i, k, s;
int main() {
  cin >> n;
  for (i = 0; i < n; ++i) {
    cin >> a[i];
    if (a[i] < a[k]) {
      k = i;
    }
    s += a[i];
  }
  n < 2 || a[k] == s - a[k] ? cout << "-1" : cout << "1 " << k + 1;
  return 0;
}
