#include <stdio.h>
long long int a[10];
long long int calc(long long int n) {
	long long int lst = 1, nxt = 1, now = 1;
	while (now < n) {
		nxt = now + lst;
		lst = now;
		now = nxt;
	}
	if (now == n) return lst;
	else return -1;
}
int main() {
	for (int i = 1; i <= 5; i++) scanf("%lld", &a[i]);
	if (a[5] == 1) {
		if (a[4] == 1) {
			for (int j = 3; j >= 1; j--) if (a[j] != a[j + 1] + a[j + 2]) {
				printf("%d\n", 5 - j);
				return 0;
			}
			printf("5\n");
		}
		else if (a[4] == 2) {
			for (int j = 3; j >= 1; j--) if (a[j] != a[j + 1] + a[j + 2]) {
				printf("%d\n", 5 - j);
				return 0;
			}
			printf("5\n");
		}
		else printf("1\n");
	}
	else {
		a[6] = calc(a[5]);
		if (a[6] == -1) printf("0\n");
		else {
			for (int j = 4; j >= 1; j--) if (a[j] != a[j + 1] + a[j + 2]) {
				printf("%d\n", 5 - j);
				return 0;
			}
			printf("5\n");
		}
	}
}