#include <bits/stdc++.h>
using namespace std;
int q;
long long x,y;
long long n;
long long gcd(long long i,long long j)
{
	return !j ? i : gcd(j,i%j);
}
int main()
{
    scanf("%d",&q);
    while(q--)
    {
    	scanf("%lld%lld",&x,&y);
    	if(x>y) swap(x,y);
    	if(x==y) 
    		printf("0\n");
    	else if(gcd(x,y)!=1) 
    	{
    		n=x/gcd(x,y)*y;
    		if(n<=x+y)
    		{
    			printf("%lld\n",n);
			}
    		else 
    			printf("%lld\n",x+y);
    	}	
		else if(x==1) 
			printf("%lld\n",y);	
		else
			printf("%lld\n",x+y);
	}
    return 0;
}