#include<stdio.h>
int k,i,p,aux,y;
long n;
FILE *f=fopen("fact.in","r"),*g=fopen("fact.out","w");
int main()
{
fscanf(f,"%d",&p);
k=0;y=1;
aux=0;
n=100000;
 for(i=1;i<=n;i++)
	{
		if(i%5==0)
		{ k++;
		aux=i;}
	if(k==p)
		break;
 }
if(aux<=25)
aux=aux-5;
 if(p!=0)
 fprintf(g,"%d",aux);
else
 fprintf(g,"%d",y);
fclose(f);
fclose(g);
return 0;
}