A child is 2 days old. He was born with a weight of 2900 kg, body length of 50 cm. On examination the skin is intensely red, elastic, with preserved turgor. Puerile respiration is present. Respiration rate - 40/min, cardiac sounds are rhythmic, sonorous. HR- 138/min. The abdomen is soft. The liver extends 2 cm below the costal margin. Diuresis is sufficient. Stool is in form of meconium. What is the most likely diagnosis?