#include <fstream>
#include <sstream>
#include <string>
#include <iostream>
using namespace std;

int main()
{
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    long long a[100];
    int i,j;
    a[0]=0;
    for (i=1; i<100; i++)
    {
        a[i]=i%10;
        for (j=1; j<i; j++) a[i]=(a[i]*(i%10))%10;
        a[i]=(a[i]+a[i-1])%10;
    }

    string s;
    int n;
    f >> n;
    for (i=0; i<n; i++)
    {

        f >> s;
        int l=s.length();
        if (l==1) g << a[s[0]-'0'] << endl;
        else
        {
            s=s.substr(l-2,2);
            g << a[10*(s[0]-'0')+s[1]-'0'] << endl;
        }
    }
}