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#include <bits/stdc++.h>
using namespace std;
int n,cnt,inp;

inline void scan(int &number)
{
    register int c;
    number = 0;
    c = getchar();
    for (; (c>47 && c<58); c=getchar()) number = number *10 + c - 48;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    scan(n);
    cnt = 0;
    while (n-- && cnt < 2)
    {
        scan(inp);
        if (inp == 1) cnt++;
    }
    cout << 2-cnt << "\n2\n1 2";
    return 0;
}