#include <iostream>
using namespace std;
int i, a, b, ile, wynik;
int main()
{
cin >> ile;
for (i=1;i<=ile;i++)
{
cin >> a >> b;
if(b%4==1)
{
wynik=a%10;
}
else if(b%4==2)
{
wynik=a%10*a%10;
}
else if(b%4==3)
{
wynik=a%10*a%10*a%10;
}
else if(b%4==0)
{
wynik=a%10*a%10*a%10*a%10;
}
cout << wynik << endl;
}
return 0;
}
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