/// Craciun Catalin
///  Cifra
///   www.infoarena.ro/problema/cifra
#include <fstream>
#include <iostream>
#include <cstring>

using namespace std;

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

#define NMax 105

int t;
int C[NMax];

int ultimaCifra(int x)
{
    int p=1;
    for (int i=1;i<=x;i++)
        p=(p*x)%10;

    return p;
}

void construireVector()
{
    for (int i=1;i<=NMax;i++)
        for (int j=1;j<=i;j++)
            C[i]=(C[i]+ultimaCifra(j))%10;
}

int main()
{
    construireVector();
    f>>t;
    for (int i=1;i<=t;i++)
    {
        char S[NMax]={NULL};
        f>>S;
        int lenghtS=strlen(S);

        if (lenghtS<10)
            g<<C[S[0]-'0']<<'\n';
        else
            g<<C[10*(S[0]-'0')+S[1]]<<'\n';
    }

    return 0;
}