#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");

int main()
{
    int p,n=0,i;
    f>>p;
    if(p==0) n=1;
    else if (p==1) n=5;
    else if (p==3) n=15;
    else {
    for(i=1;i<=p;i++) n+=5;
    }
    g<<n;

    return 0;
}

/*
2 1*2*3*4*5*6*7*8*9*10
3 1*2*3*4*5*6*7*8*9*10*11*12*13*14*15
*/