Problems > First Digit Equals Last

First Digit Equals Last

Difficulty: 1900 5000 ms 128 MB

math digit-dp

Count integers in [L, R] whose first and last decimal digits are equal.

Input: one line with two integers L and R.

Output: the count in [L, R].

Constraints:

  • 1 ≤ L ≤ R ≤ 106

Sample Tests

Input 1
1 100
Output 1
18
Input 2
11 99
Output 2
9

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