#include <iostream>
#include <fstream>
using namespace std;
fstream f("fact.in");
ofstream g("fact.out");
int p,n,i;
int main()
{
    f >> p;
    if (p==0) g << 1;
    else
    {
        for (i=1;i<=p;i++)
        {
            n+=5;
        }
        g << n;
    }
    return 0;
}