#include <stdio.h>

int main()
{
	int A, B;
	scanf("%d%d", &A, &B);

	int d[3] = { 23, 24, 25 };
	int n = 0;
	for (int i = 0; i < 3; i++) {
		if (d[i] < A || d[i] > B)
			n++;
	}

	printf("%d\n", n);
	return 0;
}