candidates = [(x * (120 - 2 * x), x, 120 - 2 * x) for x in range(61)]
area, x, y = max(candidates)
assert sum(a == area for a, _, _ in candidates) == 1
result = {"x_m": str(x), "y_m": str(y), "area_m2": str(area)}
import json
print(json.dumps(result, ensure_ascii=False, sort_keys=True))