#include <iostream>
#include<math.h>
#include<cstring>
#include<fstream>
using namespace std;
//https://www.infoarena.ro/problema/cifra
ifstream fin("cifra.in");
ofstream fout("cifra.out");

int main()
{
    int a[]= {0,1,5,2,8,3,9,2,8,7,7,8,4,7,3,8,4,1,5,4,4};
    int i,t,cifra,nr,suma=0;
    char s[128];
    fin>>t;
    fin.get();
    for(i=0; i<t; i++)
    {
        fin.getline(s,102,'\n');
        cifra=strlen(s);
        if(cifra>1)
        {
            nr=s[cifra-1]-'0'+((s[cifra-2]-'0')%2)*10;
            suma=a[nr];
            nr=(s[cifra-2]-'0');
            nr=nr-nr%2;
            nr=nr/2;
            suma=suma+(nr*a[20])%10;
            fout<<suma%10<<'\n';
        }
        else
            fout<<a[s[0]-'0']<<'\n';
    }
    fin.close();
    fout.close();
    return 0;
}