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 (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#define rep(index,num) for(int index=0;index<num;index++)
#define scan(argument) scanf("%d",&argument)
#define prin(argument) printf("%d\n",argument)
#define eps 1e-15
typedef long long ll;
int main(){
	int a,b;
	scan(a); scan(b);
	if(a*b==15) printf("*\n");
	else if(a+b==15) printf("+\n");
	else printf("x\n");
	return 0;
}