Exam#10671
Emil stayed up late playing chess with Hussein before the exam, and now he's having trouble solving a problem. Can you help him out?
You are given two integers, and . Your task is to find two integers, and , such that:
a + b = k
a - b = l
If no such integers and exist, you should output "X".
The input consists of a single line containing two integers and (-10^{18} \leq k, l \leq 10^{18}).
Print a line with the integers and separated by a space, which satisfy the conditions above. If there are no such integers, print "X".
Example 1
Example 17