#include <stdio.h>
#include <stdlib.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char *argv[]) 
{
	int shi1,shi2,fen1,fen2,n,a,b;
	scanf("%d",&n); 
	while(n--)
	{
		scanf("%d %d",&shi1,&fen1);
		scanf("%d %d",&shi2,&fen2);
		if(fen2>=fen1)
		{
			a = a+shi2-shi1;
			b = b+fen2-fen1;
			if(b>=60)
			{
				b=b-60;
				a++;
			}
			printf("%dʱ%d\n",shi2-shi1,fen2-fen1);
		}
		else
		{
			a = a+shi2-shi1;
			b = b+fen2-fen1;
			if(b>=60)
			{
				b=b-60;
				a++;
			}
			printf("%dʱ%d\n",shi2-shi1-1,60+fen2-fen1);
		}
	}
	printf("%dʱ%d\n",a,b);
	 
	return 0;
}