taxsaving.c

#include <stdio.h>

int main(void) {
	int t, x, y;
	
	scanf("%d", &t);
	while(t--) {
	    scanf("%d %d", &x, &y);
	    
	    if(x > y) {
	        printf("%d\n", x-y);
	    }
	}
	return 0;
}