input: Write a python function to estimate the value of Pi using Monte Carlo method.
  assert abs(estimate_pi(100000) - 3.14) < 0.05
  assert abs(estimate_pi(500000) - 3.14) < 0.03
  assert abs(estimate_pi(1000000) - 3.14) < 0.02
output: import random
  
  def estimate_pi(num_samples):
      inside_circle = 0
  
      for _ in range(num_samples):
          x, y = random.uniform(0, 1), random.uniform(0, 1)
          if x**2 + y**2 <= 1:
              inside_circle += 1
  
      return (inside_circle / num_samples) * 4