# Entradas
xa = float(input("Determine: "))
ya = float(input("Determine: "))
xb = float(input("Determine: "))
yb = float(input("Determine: "))
# Variavel
xm = (xb + xa) / 2
ym = (yb + ya) / 2
# Saida
print(round(xm, 1))
print(round(ym, 1))