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