Problem Description

Given a positive number up to 10 digits long, find the largest number that can be formed with the digits that's divisible by 3. If not number can be formed that is divisible by 3, return 0

Input: int Output int

Examples:

• largest_div_by_three(0) -> 0
• largest_div_by_three(24) -> 42
• largest_div_by_three(319) -> 93
• largest_div_by_three(113) -> 3
• largest_div_by_three(111) -> 0