#include <fstream>
#include <cstring>

using namespace std;

int U[100];

ifstream in("cifra.in");
ofstream out("cifra.out");

int ucif(int n)
{
    int uc=n%10,
        r=n%4,
        p=1;
    if(r==0)r=4;
    while(r--)
        p=p*uc;
    return p%10;
}

void precalcul()
{
    for(int i = 1; i < 100; i++)
        U[i] = (U[i - 1] + ucif(i)) % 10;
}

int main()
{
    int T, ncif, rest;
    char sir[101];
    precalcul();
    in >> T;
    while(T--)
    {
        in >> sir;
        ncif = strlen(sir);
        rest = sir[ncif - 1] - '0';
        if(ncif >= 2)
            rest += (sir[ncif - 2] - '0') * 10;
        out << U[rest] << '\n';
    }

    return 0;
}