a = int(input())
b = int(input())
f = (a + b) / 2
if f >= 90 and f <= 100:
    print(50)
if f >= 80 and f <= 89:
    print(30)
if f >= 70 and f <= 79:
    print(10)
if f >= 0 and f <= 69:
    print(0)
