#include <stdio.h>

int P,N;

void Olvas()
{	FILE *f=fopen("fact.in","rt");
	fscanf(f,"%d",&P);
	fclose(f);
}

void Ir()
{	FILE *f=fopen("fact.out","wt");
	fprintf(f,"%d",N);
	fclose(f);
}

void Szamol()
{	if (P==0)
		N=1;
	else if (P==1)
		N=5;
	else if (P==2)
		N=10;
	else
	{	int z=0;
		while (z<=P)
		{	N+=5;
			z++;
			if (!(N%25))
				z+=2;
			if (!(N%125))
				z+=3;
			if (!(N%625))
				z+=4;
			if (!(N%3125))
				z+=5;
			if (!(N%15625))
				z+=6;
			if (!(N%78125))
				z+=7;
			if (!(N%390625))
				z+=8;
		}
	}
}

int main()
{	Olvas();
	Szamol();
	Ir();
}