Count the number of natural numbers on the segment from a to b, the sum of whose digits is even.
Input
Enter two natural numbers a and b, not exceeding a billion (a ≤ b).
Imprint
Print one number – the number of numbers greater than or equal to a and less than or equal to b that have an even sum of digits.
Examples
| # |
Input |
Output |
| 1 |
1 5 |
2 |
| 2 |
10 10 |
0 |