def angle_complex(a,b):
  import cmath
  
  cn=complex(a,b)
  angle=cmath.phase(a+b)
  return angle
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