#include <iostream>
#include <algorithm>
#include <cstdio>
#include <fstream>
using namespace std;
FILE*f=fopen("fact.in","r");
FILE*g=fopen("fact.out","w");
int main()
{
    int p,i;
    fscanf(f,"%d",&p);
    for(p?i=5:i=2;p;i+=5)
    {
        int c=i;
        while(!(c%5))
        {
            --p;
            c/=5;
        }
    }
    fprintf(g,"%d\n",i-5);
    return 0;
}