Count Numbers With Distinct Neighbors

Count integers from left through right, including both endpoints, that have no equal neighboring digits. Use their usual decimal writing with no leading zeroes. Zero and all other single-digit numbers qualify.

Implement counting_numbers(left, right).

Input

left: The first allowed value.

right: The last allowed value.

Output

Return how many values satisfy the rule.

制約

0 ≤ left ≤ right ≤ 10¹⁸. The range may be too large to inspect each integer individually.

例

入力：
left = 10
right = 15

期待される出力：
expected = 5

入力：
long long left = 10;
long long right = 15;

期待される出力：
long long expected = 5;

入力：
long left = 10;
long right = 15;

期待される出力：
long expected = 5;

入力：
left = 0
right = 9

期待される出力：
expected = 10

入力：
long long left = 0;
long long right = 9;

期待される出力：
long long expected = 10;

入力：
long left = 0;
long right = 9;

期待される出力：
long expected = 10;

参考資料

この課題はCodeUtility用に調整されています。上記の説明と制約に従ってください。

• Counting Numbers — 2220