#include <bits/stdc++.h>

//define fin cin
//define fout cout

#define F first
#define S second
#define pii pair < int , int >

using namespace std;

typedef long long ll;

const int nmax = 5e5 + 10;

int n , i , j;
int a[nmax];

int r[nmax];

unordered_map < int , int > ap;

int main()
{
    #ifndef ONLINE_JUDGE
    freopen("input.in","r",stdin);
    freopen("output.out","w",stdout);
    #endif // ONLINE_JUDGE

    /*
    ifstream fin("input.in");
    ofstream fout("output.out");
    */

    scanf("%d", &n);
    for (i = 1; i <= n; ++i)
        scanf("%d", a + i);

    for (i = 1; i <= n; ++i)
        r[i] = (r[i-1] + a[i] % n) % n;

    ap[0] = 1;
    for (i = 1; i <= n; ++i)
    {
        if (!ap[r[i]]) ap[r[i]] = i + 1;
        else
        {
            printf("%d\n", i - ap[r[i]] + 1);
            for (j = ap[r[i]]; j <= i; ++j)
                printf("%d ", j);
            printf("\n");

            return 0;
        }
    }


    return 0;
}