A 15-year-old patient suffers from headache, nasal hemorrhages, sense of lower extremity coldness. Objectively: muscles of shoulder girdle are developed, lower extremities are hypotrophied. Pulsation on the pedal and femoral arteries is sharply dampened. AP is 150/90 mm Hg, 90/60 on the legs. Systolic murmur can be auscultated above carotid arteries. What is the most probable diagnosis?