x,t=list(map(int,input().split()))

print(("0" if x-t<0 else x-t))

x, t = list(map(int, input().split()))

print((0 if x <= t else x - t))

x, t = list(map(int, input().split()))
print(("0" if x - t < 0 else x - t))

x, t = list(map(int, input().split()))
print((0 if x <= t else x - t))

-print(("0" if x - t < 0 else x - t)) +print((0 if x <= t else x - t))