#include <iostream>
#include <cmath>
 
using namespace std;
 
int ile;
 
int main()
{
    cin >> ile;
 
    for(int i=0; i<ile; i++)
    {
        long long int a, b, e, h;
        int c, d, f, g, k;
        cin >> a >> b;
 
        if(a == 5) cout << 5 << endl;
        else if(a == 6) cout << 6 << endl;
        else
        {
        g = a%10;
        c = b/4;
        d = b-c*4;
        e = pow(g,d);
        f = e%10;
        cout << f << endl;
        }
    }
 
    return 0;
}
 

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

MTEKMTI4OTMxMjM5MSAwCjEgMjMyMTMyMzEyMwoyIDMyNDMyNDM0NQozIDQzNTQzNTQzNgo0IDkwODAyMzcKNSAyMTYzMDYyCjYgOTYxMjM0MTIKNyA5MjE2MzgxMjUKOCAyMTI4OTYzNTkxCjkgMjE1MzgxMjMKMCAxODI5MzEyNTM=

11
1289312391 0
1 2321323123
2 324324345
3 435435436
4 9080237
5 2163062
6 96123412
7 921638125
8 2128963591
9 21538123
0 182931253