#include<stdio.h>
#include<string.h>

int main(void){
    int n;
	int a,b;
	scanf("%d",&n);
	//规律数组
	int arr[6] = {2,3,2,3,2,5}; 
	while(n--){
		scanf("%d%d",&a,&b); 
		int s = a/b;
		printf("%d\n",b*arr[(s-1)%6]);
	}
    return 0;
}