Multiples of 13

Source: beecrowd

Version: Phuoc Hung OJ Extended

Problem Statement

Sum all integers in the inclusive interval between x and y that are NOT divisible by 13; reorder endpoints if necessary.

Input

Two integers in [-1000,1000] (PHOJ Extended bound).

Output

The sum of integers not divisible by 13.

Subtasks

• Subtask 1 (20%): |x|,|y|<=10.
• Subtask 2 (30%): |x|,|y|<=100.
• Subtask 3 (50%): |x|,|y|<=1000.

Examples

Example 1

Input

1
10

Output

55

Explanation

No multiple of 13 in 1..10.

Example 2

Input

12
14

Output

26

Explanation

Exclude 13 and add 12+14.