#include<iostream>
using namespace std;
int main()
{
	int n=1,p,c=0,s;
	cin>>p;
	while(c<p)
	{
		if(n==1)
			n=5;
		s=n;
		while(s!=1 && s!=0){
		if(s%5==0)
			c++;
		s=s/5;
		}
		n+=5;
	}
	cout<<n;
		
}