#include <fstream>
using namespace std;

ifstream fin("fact.in");
ofstream fout("fact.out");
int main()
{

		int p, a,c,nr;
		fin >> p;
		 a = 1;
		 c = 5;
		if (p == 0)fout << 1;
		else 
			{
				while (a < p)
			{
				c = c+5;
				nr = c;
				while(nr %5==0)
				{
					nr= nr/5;
					a++;
				}
			
			}fout <<c;
		}
		fin.close();
		fout.close();
		return 0;
}