def most_common_elem(s,a):
  from collections import Counter 
  
  most_common_elem=Counter(s).most_common(a)
  return most_common_elem
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