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

int main()
{
    ifstream fin("cifra.in");
    ofstream fout("cifra.out");

    int nr,t,sum=0,n,p,nrk,si,uj,pos,grupe;
    fin>>t;
    for(int i=0;i<t;i++)
    {
        //cum impart nr la 20
        string nr;
        fin>>nr;
        pos=(nr[nr.length()-2]-48)*10+nr[nr.length()-1]-48;
        pos=pos%20;
        if(pos<=0)
            pos+=20;
        sum=0;
        for(int j=1;j<=pos;j++)
        {
            uj=j%10;
            p=j%4;
            if(p==0)
                p=4;
            si=1;
            while(p>0)
            {
                si*=j%10;
                p--;
            }
            sum+=si%10;
            sum=sum%10;
        }
        fout<<sum%10<<endl;
    }
    return 0;
}