#include <iostream>
#include <stdio.h>
#include <math.h>
#include <algorithm>
using namespace std;

int main()
{
    int b,n,times=1 ;
    double pop ;
    int a ;
    scanf ("%d",&n) ;
    for ( int i = 0 ; i < n ; i ++ )
    {
        scanf("%d%d",&a,&b) ;
        for ( int j = 2 ; j < 9 ; j ++ )
        {
              double rem = pow(double(a),j) ;
              rem = fmod (rem , 10 ) ;
              if ( rem == a ) break ;
              times ++ ;
        }
        pop = b % times ;
        //printf("%lf\n",rem) ;
        if ( pop == 0 ) pop = times ;
        pop = pow(double(a),pop) ;
        pop = fmod (pop , 10 ) ;
        //times = pop ;
        printf("%lf\n",pop) ;
    }
    //system("PAUSE") ;
    return 0 ;
}