#include <iostream>
#include <fstream>
#include <string>
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");

int powerN2N(int n)
{
    int result = 1;
    for(int i=0;i<n;i++)
    {
        result = (result*n)%10;
    }
    return result;
}

int main()
{
    int T;
    int sum = 0;
    string s;
    string::iterator it;

    f>>T;
    for(int i=0;i<T;i++)
    {
        int number;
        sum= 0;
        f>>s;
        it = s.end()-1;
        number = (*it) - 48;
        if (it != s.begin())
            number += (*(it-1)-48)*10;

        for(int i=1;i<=number;i++)
            sum = (sum+powerN2N(i))%10;
        g<<sum<<"\n";
    }


    return 0;
}