x,y = [int(i) for i in input().split()]
x2,y2 = [int(i) for i in input().split()]
if x2 == y2:
    if abs(x) > abs(x2) and x == y:
        print(x+1)
    else:
        if x > y:
            print(x)
        else:
            print(y)
elif x > y:
    print(x)
else:
    print(y)