#include<stdio.h>
int main()
{
	long p,n,i,j;
	FILE * f;
	FILE * g;
	f=fopen("fact.in", "r");
	g=fopen("fact.out", "w");
	fscanf(f,"%ld", &p);
	if(p==0)
		fprintf(g,"1");
	else
	{
		for(i=5;i<=10000000;i+=5)
		{
			j=i;
			while(j%5==0)
			{
				p--;
				n=i;
				j=j/5;
				if(p==0)
					break;
			}
			if(p==0)
				break;
		}
		fprintf(g,"%ld", n);
	}
	fclose(f);
	fclose(g);
}