#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> v;
  for (int i = 0; i < n; i++) {
    int temp;
    cin >> temp;
    v.push_back(temp);
  }
  if (n == 1) {
    cout << -1 << endl;
    return 0;
  }
  int g = 0;
  int a = 0;
  int gri = 0;
  vector<int> ans;
  g += v[0];
  a += v[n - 1];
  gri++;
  ans.push_back(1);
  if (g >= a) {
    for (int i = 1; i < n - 1; i++) {
      g += v[i];
      gri++;
      ans.push_back(i + 1);
    }
  } else {
    for (int i = 1; i < n - 1; i++) {
      a += v[i];
    }
  }
  if (a == g) {
    cout << -1 << endl;
  } else {
    cout << gri << endl;
    for (int i = 0; i < ans.size(); i++) {
      cout << ans[i] << " ";
    }
    cout << endl;
  }
  return 0;
}
