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 Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

import java.util.*;
import java.io.*;

class Main {
  public static void main(String[] args) throws Exception{
    try (Scanner sc = new Scanner(System.in)){
      int a = sc.nextInt();
      int b = sc.nextInt();
      if (a + b == 15) {
        System.out.println("+");
      } else if (a * b == 15) {
        System.out.println("*");
      } else {
        System.out.println("x");
      }
    }
  }
}