#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream fin("fact.in");
    ofstream fout("fact.out");
    int n,i,p,x=1;
    fin>>p;
    if(p==0) fout<<"1";

    else {i=5;
    do
    {
        i+=5;
        x++;
    }while(x<p-1);
    fout<<i;}

    return 0;
}