#include <fstream>
#include <math.h>
#include <algorithm>
using namespace std;
ifstream cin("fact.in");
ofstream cout("fact.out");
int main()
{
    int p,n=0;
    cin>>p;
    if(p==0)
        cout<<1;
    else
    {
        while(p)
        {
            n=n+5;
            p--;
        }
        if(n%10==0)
            cout<<n;
        else
            cout<<n-5;
    }
}