#include<stdio.h>
int main()
{long unsigned i,k,p,a=100,r=2;
FILE *f=fopen("fact.in","r");
FILE *g=fopen("fact.out","w");
fscanf (f,"%ld",&p);
if (p==0) fprintf(g,"1");
else {i=0;k=0;
		while (k<p)
			{i=i+5;
			if (i>a) {a=a*10; r++;}
			if (i%10==0){ k++; if (i%100==0) {k++; if (i%1000==0) {k++; if (i%10000==0) {k++; if (i%100000==0) {k++; if (i%1000000==0) k++;}  }  }}}
			else if (i%100==25)k+=r;
			else k++;   }  }
fprintf (g,"%ld",i);
fclose(f);
fclose(g);
return 0;}