#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    FILE* f=fopen("fact.in","r");
    FILE* g=fopen("fact.out","w");
    int n;
    int k=0;
    fscanf(f,"%d",&n);
    if(n==0)
    {
        fprintf(g,"1");
    }
    long long numar=n*5;
    for(long long i=5; i<=numar; i=i+5)
    {
        long long nr=i;
        while(nr%5==0)
        {
            nr/=5;
            k++;
        }
        if(k==n)
        {
            fprintf(g,"%d",i);
            break;
        }
    }
}