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#include <algorithm>
#include <stdio.h>

int main()
{
    int n, tmp, onesCount = 0;
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) {
        scanf("%d", &tmp);
        if (tmp == 1) {
            onesCount++;
        }
    }
    printf("%d\n", std::max(2 - onesCount, 0));
    printf("2\n");
    printf("1 2\n");
    return 0;
}