#include <iostream>

using namespace std;
long int a,b;
int c,ile;
int main()
{
    cin>>ile;
    for(int i=1;i<=ile;i++)
    {
    cin>>a>>b;
    while(c!=2 && c!=3 && c!=7 && c!=8)
    {
    c=a%10;
    if(c==1)
        cout<<1<<endl;
    if (c==4)
    {
        if(b%2==0)
            cout<<"6"<<endl;
        else
            cout<<"4"<<endl;
    }
    if(c==5)
        cout<<"5"<<endl;
    if (c==6)
        cout<<"6"<<endl;
    if(c==9)
    {
        if(b%2==0)
            cout<<"1"<<endl;
        else
            cout<<"9"<<endl;
    }
    if(c==0)
        cout<<0<<endl;
    }

                while (b%4==0)
    {
        switch (c)
    {
        case 2:
        case 8:
            cout<<"6"<<endl;break;
        case 3:
        case 7:cout<<"1"<<endl;break;
    }
    }
         while (b%4==1)
    {
        switch (c)
    {
        case 2:cout<<"8"<<endl;break;
        case 8: cout<<"2"<<endl;break;
        case 3:cout<<"7"<<endl;break;
        case 7:cout<<"3"<<endl;break;
    }
    }
     while (b%4==2)
    {
        switch (c)
    {
        case 2:
        case 8: cout<<"4"<<endl;break;
        case 3:
        case 7:cout<<"9"<<endl;break;
    }

      }
       while (b%4==3)
    {
        switch (c)
    {
        case 2:cout<<"2"<<endl;break;
        case 8: cout<<"8"<<endl;break;
        case 3:cout<<"3"<<endl;break;
        case 7:cout<<"7"<<endl;break;
    }


    }
    }
    return 0;
    }