MAXIMISE THE VALUE

Given two positive integers a and b, we define f(a,b) = lcm(a,b)− gcd(a,b), where lcm denotes the lowest common multiple and gcd denotes the greatest common divisor. Chef has a positive integer N. He wonders, what is **the maximum value of f(a,b) over all pairs (a,b)** such that a and b are positive integers, and **a+b=N ?** ### Input * The first line of input will contain an integer T — the n