#include <stdio.h>
#include <math.h>
int main(void) {
	int t, n, m, k;
	scanf("%d",&t);
	while(t--){
		scanf("%d%d",&n,&m);
		k = m/(float)n*100+1;
		if(k<100) printf("%d\n",(int)ceil((double)(100*m-k*n)/(k-100)));
		else printf("-1\n");
	}
	return 0;
}