#include<bits/stdc++.h>
using namespace std;
int main(){
	int T;
	int h1,h2,m1,m2;
	scanf("%d",&T);
	while(T--){
		scanf("%d:%d",&h1,&m1);
		scanf("%d:%d",&h2,&m2);
		int t1 = h1*60+m1;
		int t2 = h2*60+m2;
		int c;
		if(t2>=t1)  c = t2-t1;
		else c = t2+1440-t1;
		printf("%d\n",c);
	}
	return 0; 
}