#include <iostream>
#include <fstream>
using namespace std;
ifstream in("fact.in");
ofstream out("fact.out");
void fact(int n)
{
    if(n>0&&n<100000000)
    {
        int i,k,c=0,p=0;
        for(k=0;k<n;k++)
        {
            c=c+5;
            if(c%100==25||c%100==75)
                p++;
        }
        out<<c-p*5;
    }
    else if(n==0)
        out<<1;
    else if(n<0||n>100000000)
        out<<-1;
}
int main()
{
    int n;
    in>>n;
    in.close();
    fact(n);
    return 0;
}