#define _CRT_SECURE_NO_WARNINGS
#include <cstdio>
#include<stdlib.h>
int main() {
	int a, b, c, d, e, f, x, y;
	scanf("%d%d%d%d", &a, &b, &c, &d);
	int i = 0;
	if (a < 0 || a>23)
		i = 1;
	if (b < 0 || b>59)
		i = 2;
	if (c < a || c>23)
		i = 3;
	x = 60 * a + b;
	y = 60 * c + d;
	if (x > y)
		i = 4;
	if (i != 0)
	{		printf("%d", i);
	exit(0);
}
	if(d>b)
	{
		e = c - a; f = d - b;
	}
	else { a += 1; d += 60;
	e = c - a; f = d - b;
	}
	printf("%d小时%d分钟\n", e, f);
}