We have a sandglass that runs for X seconds. The sand drops from the upper bulb at a rate of 1 gram per second. That is, the upper bulb initially contains X grams of sand.  How many grams of sand will the upper bulb contains after t seconds?
a,b=map(int,input().split());print(min(0,a-b))
x,t=map(int,input().split())
print(max(0,x-t))