a,b=map(int,input().split());print(-(a^b)>>1&1^~b%2*b^a%2*a) a,b=map(int,input().split()) a map(int,input().split()) map int input().split() ().split () input split b print(-(a^b)>>1&1^~b%2*b^a%2*a) print -(a^b)>>1&1^~b%2*b^a%2*a -(a^b)>>1&1^~b%2*b -(a^b)>>1&1 -(a^b)>>1 -(a^b) a^b a b 1 1 ~b%2*b ~b%2 ~b b 2 b a%2*a a%2 a 2 a a,b=map(int,input().split()) map(int,input().split()) a b=map(int,input().split()) map(int,input().split()) b
a,b=map(int,input().split());print(-(a^b)>>1&1^~b%2*b^a%2*a)