#include <stdio.h>

#include <stdio.h>

int main() {
	int p,i=0,doi=0,cinci=0,n;
	FILE *in,*out;
	
	if((in=fopen("fact.in","r"))==NULL) {
										   printf("fisier inaccesibil\n");
										   exit(1);
										   }
	fscanf(in,"%d",&p);
	fclose(in);
	
	while(1) {
			 i++;
			 n=i;
			  while(!(i%2)) {
			  				doi++;
			  				i/=2;
							}
			  while(!(i%5)) {
			  				cinci++;
			  				i/=5;
							}
			  if ((doi>=p) && (cinci>=p)) break;
			  i=n;
			  }
			 
	
	
	if((out=fopen("fact.out","w"))==NULL){
 											 printf("fisier inaccesibil\n");
										   	 exit(1);
										   }
	fprintf(out,"%d",n);
	fclose(out);
	return 0;
}