#include <iostream>
using namespace std;
int main()
{
long a,b,test,reszta;
cin>>test;
for(int i=1;i<=test;i++)
{
cin>>a>>b;
if(b==0)
cout<<"1";
reszta=a%10;
if(reszta==0)
cout<<"0";
if(reszta==1)
cout<<"1";
if(reszta==5)
cout<<"5";
if(reszta==6)
cout<<"6";
if(reszta==4)
{
if(b%2==0)
cout<<"6"<<endl;
else
cout<<"4"<<endl;
}
if(reszta==2)
{
if(b%4==0)
cout<<"6"<<endl;
if(b%4==1)
cout<<"2"<<endl;
if(b%4==2)
cout<<"4"<<endl;
if(b%4==3)
cout<<"8"<<endl;
}
if(reszta==3)
{
if(b%4==0)
cout<<"1"<<endl;
if(b%4==1)
cout<<"3"<<endl;
if(b%4==2)
cout<<"9"<<endl;
if(b%4==3)
cout<<"7"<<endl;
}
if(reszta==7)
{
if(b%4==0)
cout<<"1"<<endl;
if(b%4==1)
cout<<"7"<<endl;
if(b%4==2)
cout<<"9"<<endl;
if(b%4==3)
cout<<"3"<<endl;
}
if(reszta==8)
{
if(b%4==0)
cout<<"6"<<endl;
if(b%4==1)
cout<<"8"<<endl;
if(b%4==2)
cout<<"4"<<endl;
if(b%4==3)
cout<<"2"<<endl;
}
if(reszta==9)
{
if(b%2==0)
cout<<"1"<<endl;
else
cout<<"9"<<endl;
}
}
}
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