#include <bits/stdc++.h>
using namespace std;
const int N = (int)2e5 + 5;
const int INF = (int)1e9 + 7;
int dx[8] = {1, 0, -1, 0, -1, -1, 1, 1};
int dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
int ini() {
  int x;
  scanf("%d", &x);
  return x;
}
long long inl() {
  long long x;
  scanf("%lld", &x);
  return x;
}
int a[100009];
pair<int, int> p[1009];
int main() {
  int n, i, j;
  n = ini();
  for (i = 1; i <= n; i++) {
    cin >> a[i];
    p[i] = {a[i], i};
  }
  sort(p + 1, p + n + 1);
  if (n == 1) {
    cout << "-1" << endl;
  } else if (n == 2) {
    if (a[1] == a[2]) {
      cout << "-1" << endl;
    } else {
      cout << 1 << endl;
      cout << 1 << endl;
    }
  } else {
    cout << n - 1 << endl;
    for (i = n; i > 1; i--) cout << p[i].second << " ";
  }
  return 0;
}
