#include <iostream>
using namespace std;
int n, a ,b, wynik;
long int potega(int a, int b)
{
wynik=1;
while (b>0)
{
wynik=wynik*a;
b--;
} return wynik;
}
int main()
{
cin>>n;
for(int i=1; i<=n; i++)
{
cin>>a>>b;
cout<<potega(a,b)%10<<endl;
}
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgoKdXNpbmcgbmFtZXNwYWNlIHN0ZDsKaW50IG4sIGEgLGIsIHd5bmlrOwpsb25nIGludCBwb3RlZ2EoaW50IGEsIGludCBiKQp7CiAgICB3eW5paz0xOwogICAgd2hpbGUgKGI+MCkKICAgIHsKICAgICAgICB3eW5paz13eW5payphOwogICAgICAgIGItLTsKICAgIH0gcmV0dXJuIHd5bmlrOwp9CmludCBtYWluKCkKewogICAgY2luPj5uOwogICAgZm9yKGludCBpPTE7IGk8PW47IGkrKykKICAgIHsKICAgICAgICBjaW4+PmE+PmI7CiAgICAgICAgY291dDw8cG90ZWdhKGEsYiklMTA8PGVuZGw7CiAgICB9CiAgICByZXR1cm4gMDsKfQo=