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


class Program {

	const long mod = 1000000007;
	//public static int[] max;

	static void Main(string[] args) {

		char[] cs = new char[] { ' ', ',' };
		//int val = int.Parse(Console.ReadLine());
		//int[] vals = parseAry(Console.ReadLine().Split(cs));
		//string str = Console.ReadLine();
		//string[] strs = Console.ReadLine().Split(cs);

		//string res="";
		//int res = 0; ;
		//int n = int.Parse(Console.ReadLine());
		int[] vals = parseAry(Console.ReadLine().Split(cs));
		//string str = Console.ReadLine();

		if ( vals[0] + vals[1] == 15 ) {

			Console.WriteLine("+");
			return;
		}


		if ( vals[0] * vals[1] == 15 ) {

			Console.WriteLine("*");
			return;
		}
		//for ( int i = 0; i < n; i++ ) {

		//}



		Console.WriteLine("x");

		return;
	}


	//　String[]  ----->  int[]
	static int[] parseAry(string[] str) {
		int[] nums = new int[str.Length];
		for (int i = 0; i < str.Length; i++) { nums[i] = int.Parse(str[i]); }
		return nums;
	}
	//　String[]  ----->  long[]
	static long[] parseAryL(string[] str) {
		long[] nums = new long[str.Length];
		for (int i = 0; i < str.Length; i++) { nums[i] = long.Parse(str[i]); }
		return nums;
	}
	
	//文字列を1文字ずつString[]に入れる
	static string[] strAry(String str) {
		string[] re = new string[str.Length];
		for (int i = 0; i < str.Length; i++) { re[i] = str[i].ToString(); }
		return re;
	}

}