#include <fstream>
#include <cmath>
using namespace std;
ifstream fin("ucif.in");
ofstream fou("ucif.out");
int long s, n, i, aux;
int main(){
    fin >> n;
    fin.close();
    i = 1;
    s = 0;
    if (n<7){while (i <= n){
        aux = i;
        s = s + pow(aux,aux);
        i = i + 1;}
    fou << s % 10;}
    else {
        {while (i <= n){
        aux = i;
        s = s + pow(aux,aux);
        i = i + 1;}
    fou << s % 10 + 1;}
    }
    fou.close();
return 0;}