#include <stdio.h>
main(void)
{
  long i,n;
  double a=0, b;
  printf("何回繰り返す？");
  scanf("%d",&n);
  b=1;
  for (i=1; i<=n; i++) {
    a += 1 / b;
    b = b*i;
  }
  printf("e is nearly %.20f\n", a);
}