Digit Sum

문제

For a pair of integers a and b, the digit sum of the interval [a, b] is defined as the sum of all digits occurring in all numbers between (and including) a and b. For example, the digit sum of [28, 31] can be calculated as:

2+8 + 2+9 + 3+0 + 3+1 = 28

Given the numbers a and b, calculate the digit sum of [a, b].

입력

On the first line one positive number: the number of test cases, at most 100. After that per test case:

• one line with two space-separated integers, a and b (0 ≤ a ≤ b ≤10¹⁵)

출력

Per test case:

• one line with an integer: the digit sum of [a, b].

3
0 10
28 31
1234 56789

46
28
1128600