A full-term neonate weighing 4500 g was born asphyxiated with Apgar score of 4-6 points. During the delivery shoulder dystocia occurred. Neurologic assessment revealed non-focal neurologic symptoms, total flaccid paresis of the upper extremities since the arm was atonic and pronated. Grasping, Babkin's and Moro's reflexes were absent. What segments of spinal cord had been affected?