#include <iostream>
#define N 20
using namespace std;
int potega(int a, int b);
int main()
{
    int D;
    int tab[N], wyniki[N];
    cin >> D;
    for(int i=0;i<2*D;i+=2){
        cin >> tab[i] >> tab[i+1];
        tab[i+1] = tab[i+1]%4;
    }
    for(int i=0,n=0;i<2*D;i+=2,n++){
       wyniki[n] = potega(tab[i],tab[i+1]);
    }
    for(int n=0;n<D;n++){
        cout << wyniki[n]%10 << endl;
    }


}
int potega(int a, int b){
    if(b==0)
        return 1;
    else
        return a=a*potega(a,--b);
}