Problem:
Score : 100 points

Problem Statement

You are given two integers a and b.
Determine if a+b=15 or a\times b=15 or neither holds.

Note that a+b=15 and a\times b=15 do not hold at the same time.

Constraints

1 \leq a,b \leq 15

All values in input are integers.

Input

Input is given from Standard Input in the following format:

a b

Output

If a+b=15, print +;
if a\times b=15, print *;
if neither holds, print x.

Sample Input 1

4 11

Sample Output 1

+

4+11=15.

Sample Input 2

3 5

Sample Output 2

*

3\times 5=15.

Sample Input 3

1 1

Sample Output 3

x

1+1=2 and 1\times 1=1, neither of which is 15.

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io;

fn main() {
    let mut input_string = String::new();
    io::stdin()
        .read_line(&mut input_string)
        .unwrap();
    let input_ints: Vec<u8> = input_string.trim().split(" ")
        .map(|s| s.parse::<u8>().unwrap())
        .collect();
    let (a, b) = (input_ints[0], input_ints[1]);

    let output = if a+b == 15 { "+" }
                 else if a*b == 15 { "*" }
                 else { "x" };
    println!("{}", output);
}