Days in a Month

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given month m and year y in the Gregorian calendar, months 1,3,5,7,8,10,12 have 31 days and 4,6,9,11 have 30. February has 29 days in a leap year and 28 otherwise. A leap year is divisible by 400 or divisible by 4 but not by 100.

Input

One line contains integers m and y, the month and year.

Output

Print the number of days in month m of year y.

Subtasks

• Subtask 1 (20%): m = 2, 1900 <= y <= 2024.
• Subtask 2 (30%): 1 <= m <= 12, 1900 <= y <= 2024.
• Subtask 3 (50%): 1 <= m <= 12, 1 <= y <= 9999.

Examples

Example 1

Input

2 2000

Output

29

Explanation

Year 2000 is divisible by 400, so February has 29 days.

Example 2

Input

2 1900

Output

28

Explanation

Year 1900 is divisible by 100 but not 400, so February has 28 days.