#include<stdio.h>

int gcd(int a,int c){
	int r;
	r=a%c;
	while(r){
		a=c;
		c=r;
		r=a%c;
	}
	return c;
}

int main(void){
	int a,b,c,n;
	scanf("%d",&n);
	while(n){
		n-=1;
		scanf("%d %d",&a,&b);
		c=b*2;
		while(gcd(a,c)!=b){
			c+=b;
		}
		printf("%d\n",c);
	}
	return 0;
}