def harmonic_sum(n):
  
  if n < 2:
    return 1
  else:
    return 1 / n + (harmonic_sum(n - 1))
def is_not_prime(n):
    import math
    
    result = False
    for i in range(2,int(math.sqrt(n)) + 1):
        if n % i == 0:
            result = True
    return result