#include <bits/stdc++.h>
double a[200009];
int b[200009];
int main() {
  double s, k;
  int i, e, r, m;
  memset(b, 0, sizeof(b));
  scanf("%d", &m);
  s = 0;
  e = 0;
  r = 0;
  for (i = 0; i < m; i++) {
    scanf("%lf", &a[i]);
    s += a[i];
  }
  for (i = 0; i < m; i++) {
    k = (s - a[i]) / (m - 1);
    if (k == a[i]) {
      b[i] = i + 1;
      e++;
    }
  }
  printf("%d\n", e);
  if (e) {
    for (i = 0; i < m; i++) {
      if (b[i] != 0 && r != e) {
        printf("%d ", b[i]);
        r++;
      } else if (r == e && b[i] != 0)
        printf("%d\n", b[i]);
    }
  }
  return 0;
}
