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