#include<stdio.h>int main(void){

int t,a,aa;long b;scanf("%d",&t);while(t--){

scanf("%d %ld",&aa,&b);a=aa%10;

// b=bb%10;switch(a){

case 1:printf("1\n");break;case 2: if(b%4==0)

printf("6\n");else if(b%3==0)printf("8\n");else if(b%2==0)printf("4\n");elseprintf("2\n");

break;case 3: if(b%4==0)

printf("1\n");else if(b%3==0)printf("7\n");else if(b%2==0)printf("9\n");elseprintf("3\n");

break;case 4: if(b%2==0)

printf("6\n");elseprintf("4\n");

break;case 5: printf("5\n");break;case 6: printf("6\n");break;case 7: if(b%4==0)

printf("1\n");else if(b%3==0)printf("3\n");else if(b%2==0)printf("9\n");elseprintf("7\n");

break;case 8: if(b%4==0)

printf("6\n");else if(b%3==0)printf("2\n");else if(b%2==0)printf("4\n");elseprintf("8\n");

break;

case 9: if(b%2==0)printf("1\n");elseprintf("9\n");

break;case 0: printf("0\n");break;

}}

}