#include <bits/stdc++.h>
using namespace std;
const int MAXN = 20;
int n, A[MAXN];
int main() {
  while (scanf("%d", &n) >= 1) {
    for (int i = (0); i < (int)(n); i++) scanf("%d", &A[i]);
    if (n == 1) {
      printf("-1\n");
      continue;
    }
    if (n == 2) {
      if (A[0] == A[1])
        printf("-1\n");
      else
        printf("1\n1\n");
      continue;
    }
    int s = 0, t = n - 1;
    for (int i = (0); i < (int)(n - 1); i++) s += A[i];
    if (s == A[n - 1]) t--;
    printf("%d\n", t);
    for (int i = (0); i < (int)(t); i++) {
      if (i) printf(" ");
      printf("%d", i + 1);
    }
    puts("");
  }
  return 0;
}
