#include<cstdio>

int main() {
	int n;
	scanf("%d", &n);
	int ones = 0;
	for (int i = 0; i < n; ++i) {
		int x;
		scanf("%d", &x);
		if (x == 1) {
			++ones;
		}
	}
	printf("%d\n2\n1 2\n", ones >= 2 ? 0 : 2 - ones);
	return 0;
}

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#include<cstdio>

int main() {
	int n;
	scanf("%d", &n);
	int ones = 0;
	for (int i = 0; i < n; ++i) {
		int x;
		scanf("%d", &x);
		if (x == 1) {
			++ones;
		}
	}
	printf("%d\n2\n1 2\n", ones >= 2 ? 0 : 2 - ones);
	return 0;
}