#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
int main()
{
int c,n,s,v[10000],i;
ifstream fin("cifra.in");
ofstream fout("difra.out");
fin>>c;
fin>>n;
while(c!=0)
   {
    s=0;
    while (n!=0)
        {
        v[n]=pow(n,n);
        s=s+v[n];
        n--;
        }
    fout<<s%10<<endl;
    fin>>n;
    c--;
   }

return 0;
}