Select an Arithmetic Operation

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given integers a and b and operator character op, compute a+b, a-b or a*b for +, - or *, respectively. For any other operator print INVALID. Preserve operand order for subtraction.

Input

One line contains integers a and b followed by a non-whitespace operator character.

Output

Print the integer result on one line for +, - or *; otherwise print INVALID.

Subtasks

• Subtask 1 (20 points): 0 <= a,b <= 10 and op is +.

• Subtask 2 (30 points): -100 <= a,b <= 100 and op is + or -.

• Subtask 3 (50 points): -10000 <= a,b <= 10000; op is visible ASCII 33–126.

Examples

Example 1

Input

5 -2 -

Output

7

Explanation

For subtraction, 5 - (-2) equals 7.

Example 2

Input

3 4 /

Output

INVALID

Explanation

Slash is not among the supported operators, so print INVALID.