Given three ints, a b c, return true if one of b or c is "close" (differing from a by at most 1), while the other is "far", differing from both other values by 2 or more. Note: Math.abs(num) computes the absolute value of a number.

closeFar(1, 2, 10) → true
closeFar(1, 2, 3) → false
closeFar(4, 1, 3) → true