input: Write a python function to create a random matrix with given dimensions.
  assert len(random_matrix(2, 2)) == 2 and len(random_matrix(2, 2)[0]) == 2
  assert len(random_matrix(3, 4)) == 3 and len(random_matrix(3, 4)[0]) == 4
  assert len(random_matrix(5, 5)) == 5 and len(random_matrix(5, 5)[0]) == 5
output: import random
  
  def random_matrix(rows, cols):
      return [[random.randint(0, 100) for _ in range(cols)] for _ in range(rows)]