A boy is 8-year-old. His physical development is compliant with his age. The child has had cardiac murmur since birth. Objectively: skin and visible mucous membranes are of normal colour. AP- 100/70 mm Hg. Auscultation revealed systolo-diastolic murmur and diastolic shock above the pulmonary artery. ECG shows overload of the left heart. Roentgenoscopy shows coarsening of the lung pattern, heart shadow of normal form. What is the most likely diagnosis?