#include <stdio.h>
int n, nr0,i2;
int i; // Contor
FILE *in, *out;
int main(void)
{
    in=fopen("fact.in","rt");
    out=fopen("fact.out","wt");
    fscanf(in, "%d",&n);
    if(!n)
        fprintf(out, "1");
  else
  {
        for(i=0;i<=2000000000;i+=5)
    {
        i2=i;
        while( !(i2%5) && i2 )
        {
            nr0++;
            i2/=5;
            if(nr0==n)
                break;
        }
        if(nr0==n)
            break;
    }
    fprintf(out, "%d",i);
  }

    fclose(in);
    fclose(out);
    return 0;
}