#include <iostream>
#include <math.h>
#include <fstream>
using namespace std;
int main()
{
    int n,i,sum;
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    f >> n;
    while(f>>n)
    {
        sum=0;
        for(i=1;i<=n;i++)
        {
            sum=sum+pow(i,i);
            sum=sum%10;
        }
        g <<sum << endl;
    }
    return 0;
}