Problem Description

Given two integers \( a, b \). Determine whether \( a + b = 15 \) or \( a \times b = 15 \), or neither.

Note that \( a + b = 15 \) and \( a \times b = 15 \) cannot hold simultaneously.

Input Format

The input is given from the standard input in the following format:

\( a \) \( b \)

Output Format

If \( a + b = 15 \), output +. If \( a \times b = 15 \), output *. If neither, output x.

Sample Input and Output

Sample Input #1

4 11

Sample Output #1

+

Sample Input #2

3 5

Sample Output #2

*

Sample Input #3

1 1

Sample Output #3

x

Notes/Hints

Constraints

• \( 1 \leq a, b \leq 15 \)
• All inputs are integers

Sample Explanation 1

\( 4 + 11 = 15 \).

Sample Explanation 2

\( 3 \times 5 = 15 \).

Sample Explanation 3

\( 1 + 1 = 2 \) and \( 1 \times 1 = 1 \), neither of which equals 15.

见题面 Input 部分

见题面 Output 部分