Independent Operations by Code

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given an operation code m and two integers a and b, code 1 requests a+b, code 2 requests a-b, and code 3 requests the larger of a and b (the common value if they are equal). Any other code prints INVALID. Perform exactly one operation.

Input

One line contains three integers m, a and b, in that order.

Output

Print the integer result, or exactly INVALID for an unknown operation code.

Subtasks

• Subtask 1 (20%): m = 1 and 0 <= a,b <= 10.
• Subtask 2 (30%): 1 <= m <= 3 and -100 <= a,b <= 100.
• Subtask 3 (50%): -10 <= m <= 10 and -10^6 <= a,b <= 10^6.

Examples

Example 1

Input

3 7 7

Output

7

Explanation

Code 3 requests the maximum. Both values are 7, so the answer is 7.

Example 2

Input

2 -4 9

Output

-13

Explanation

Code 2 subtracts b from a: -4-9=-13.

Example 3

Input

9 2 3

Output

INVALID

Explanation

Code 9 is not a supported operation.