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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

public class Main {

	public static void main(String[] args) {
		// make new Scanner.
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.next());
		int t = Integer.parseInt(sc.next());
		
		if (n + t == 15 ) {
			System.out.println('+');
		} else if (n * t == 15) {
			System.out.println('*');
		} else {
			System.out.println('x');
		}
		
		// Listに格納.
//		List<Integer> list = inList(sc,n);
		

		// close Scanner
		sc.close();

	}

	
	/**
	 *  入力した数字を配列に格納するメソッド.
	 * @param sc
	 * @param n
	 * @return
	 */
	public static List<Integer> inList(Scanner sc, int n) {
		List<Integer> list = new ArrayList<Integer>();
		for (int a=0;a<n;a++) {
			list.add(sc.nextInt());
		}
		return list;
	}

}