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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++;
	}
	if (ones >= 2) {
		printf("0\n");
	}
	else if (ones == 1) {
		printf("1\n");
	}
	else {
		printf("2\n");
	}
	printf("2\n1 2\n");
}