Arithmetic Operation Check

Given three integers (a), (b), and (c) such that (b \neq 0), perform the following checks:

• If \(a + b = c\), output plus.
• If \(a - b = c\), output minus.
• If neither condition holds, output illegal.

Note: The inputs are given in a single line separated by spaces.

inputFormat

A single line containing three integers (a), (b), and (c) separated by spaces. It is guaranteed that (b \neq 0).

outputFormat

Output a single word which is either plus (if (a + b = c)), minus (if (a - b = c)), or illegal (if neither condition is satisfied).

sample

1 2 3

plus