Xa = float(input('digite Xa: '))
Ya = float(input('digite Ya: '))
Xb = float(input('digite Xb: '))
Yb = float(input('digite Yb: '))

Xm = (Xb+Xa)/2
Ym = (Yb+Ya)/2

print(round(Xm,1))
print(round(Ym,1))