Integer Calculator with Remainder

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given integers a and b and an operator op, compute addition, subtraction, multiplication, integer division or remainder for +, -, *, / or %. C integer division truncates toward zero and its remainder satisfies a = (a/b)*b + a%b. For / or % with b = 0, print DIV0; for other operators print INVALID.

Input

One line contains integers a, b, followed by one operator character op, in that order.

Output

Print the integer result, or DIV0 for zero divisor with / or %, or INVALID for an unsupported operator.

Subtasks

• Subtask 1 (20%): 0 <= a,b <= 20 and op is + or -.
• Subtask 2 (30%): -100 <= a,b <= 100 and op is one of +, -, *, / or %.
• Subtask 3 (50%): -10^6 <= a,b <= 10^6 and op is one non-whitespace ASCII character.

Examples

Example 1

Input

-7 3 %

Output

-1

Explanation

C truncates -7/3 to -2, giving remainder -1.

Example 2

Input

12 0 /

Output

DIV0

Explanation

Since division by zero is invalid, print DIV0.