input: Write a python function to generate a random matrix of size n x m with values between 1 and 100.
  assert len(random_matrix(3, 2)) == 3
  assert len(random_matrix(3, 2)[0]) == 2
  assert isinstance(random_matrix(3, 2)[0][0], int)
output: import random
  
  def random_matrix(n, m):
      return [[random.randint(1, 100) for _ in range(m)] for _ in range(n)]