#include <bits/stdc++.h>
using namespace std;
int main() {
  int npackets;
  scanf("%d", &npackets);
  if (npackets < 2) {
    printf("-1");
    return 0;
  }
  vector<int> pack(npackets);
  int i, i_min = 0;
  for (i = 0; i < npackets; i++) {
    scanf("%d", &pack[i]);
    if (pack[i] < pack[i_min]) i_min = i;
  }
  if (npackets == 2) {
    if (pack[0] == pack[1]) {
      printf("-1");
    } else {
      printf("1\n1");
    }
    return 0;
  }
  printf("%d\n", npackets - 1);
  for (i = 0; i < npackets; i++) {
    if (i != i_min) printf("%d ", i + 1);
  }
  return 0;
}
