X = df.copy()
y = X.pop("CompressiveStrength")

# Train and score baseline model
baseline = RandomForestRegressor(criterion="mae", random_state=0)
baseline_score = cross_val_score(
    baseline, X, y, cv=5, scoring="neg_mean_absolute_error"
)
baseline_score = -1 * baseline_score.mean()

print(f"MAE Baseline Score: {baseline_score:.4}")