#include<stdio.h>
int gcd(int a,int b){
	int c,r;
	r=a%b;
	while(r){
		a=b;
		b=r;
		r=a%b;
	}
	return b;
}
int main(void){
	int n,a,b,c;
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		scanf("%d %d",&a,&b);
		c=2*b;
		while(gcd(a,c)!=b){
			c=c+b;
		}
		printf("%d\n",c);
	}
	return 0;
}