#include<stdio.h>
long p;
FILE*f=fopen("factorial.in","r"),*g=fopen("factorial.out","w");

void citire(){
    fscanf(f,"%ld ",&p);
	fclose(f);
}

void aflare_n(){
	long n_2=2,n_5=5,x,y,nr_2=0,nr_5=0;
    for(long i=1;i<=p;i++){
		x=n_2;
	   while(x%2==0){
	       nr_2++;
		   x/=2;
	   }
	   y=n_5;
	   while(y%5==0){
	       nr_5++;
		   y/=5;
	   }
	   if(nr_2>=p&&nr_5>=p){break;}
	   n_2+=2;
	   n_5+=5;
	}
	if(p==0){
	  fprintf(g,"1 ");
	}
	else{
	   fprintf(g,"%ld ",n_5);
	}
	
	fclose(g);
}

int main(){
	citire();
	aflare_n();
return 0;
}