#include <stdio.h>

#define MAX_N 400001

long long numbers[MAX_N], reminders[MAX_N], n, sum, reminder;

int main() {
  scanf("%d", &n);
  for (int it = 0; it < n; ++it) {
    scanf("%d", &numbers[it]);
  }

  for (int it = 0; it < n; ++it) {
    sum += numbers[it];
    reminder = sum % n;

    if (reminder == 0) {
      printf("%d\n", it + 1);
      for (int jt = 1; jt <= it + 1; ++jt) {
        printf("%d ", jt);
      }
      return 0;
    }

    if (reminders[reminder] != 0) {
      printf("%d\n", it + 1 - reminders[reminder]);
      for (int jt = reminders[reminder] + 1; jt <= it + 1; ++jt) {
        printf("%d ", jt);
      }
      return 0;
    }

    reminders[reminder] = it + 1;
  }
}