def forward_pass(X, W1, b1, W2, b2):
    """Complete forward pass through the network"""
    # Hidden layer
    z1 = X @ W1 + b1              # Linear transformation
    a1 = sigmoid(z1)              # Activation

    # Output layer
    z2 = a1 @ W2 + b2            # Linear transformation
    a2 = sigmoid(z2)             # Activation

    return z1, a1, z2, a2

# Test forward pass
z1, a1, z2, predictions = forward_pass(X, W1, b1, W2, b2)
print(f"Predictions shape: {predictions.shape}")
print(f"Predictions:\n{predictions.flatten()}")
print(f"Actual labels:\n{y.flatten()}")