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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SoundHound_Inc
{
    class Program
    {
        static void Main(string[] args)
        {
            int a, b, c, d, f;
            var word = Console.ReadLine().Split(' ');
            a = int.Parse(word[0]);
            b = int.Parse(word[1]);
            c = a + b;
            d = a * b;
            f = 15;

            if (!(c > f )&&( !(c < f)))
            {

                Console.WriteLine("+");
            }
            else if (!(d > f )&& (!(d < f)))
            {
                Console.WriteLine("*");
            }
            else
            {
                Console.WriteLine("x");
            }
            Console.ReadKey();

        }
    }
}