You are given an operation that changes an integer to the sum of the square of all its digits. This operation can be applied to a positive integer as many times as you like.
If a number can become $$$1$$$ after any amount of operations (possibly zero), it is said to be a happy number. A happy number, for instance, is $$$13$$$, which becomes $$$10(1^2 + 3^2 = 10)$$$ after one operation and becomes $$$1(1^2 + 0^2 = 1)$$$ after one more operation. However, $$$2, 3$$$, and $$$4$$$ are not happy numbers.
You are given $$$t$$$ closed intervals, each represented by two integers $$$l_i$$$ and $$$r_i$$$ $$$(1 \leq i \leq t)$$$. For each interval, please determine the number of happy numbers in the interval.
Formally, for each query $$$i$$$, please compute
$$$$$$\sum_{x=l_i}^{r_i}f(x)$$$$$$
where $$$f(x)=1$$$ if $$$x$$$ is a happy number and $$$f(x)=0$$$ if $$$x$$$ is not a happy number.
Since the answers can be very large, please print them modulo $$$10^9+7$$$.
The first line contains one integer $$$t$$$ $$$(1 \leq t \leq 100)$$$ — the number of test cases.
The only line of each test case contains two integers $$$l_i, r_i$$$ $$$(1 \leq l_i \leq r_i \leq 10^{200})$$$.
It is guaranteed that the sum of the lengths of all inputted integers does not exceed $$$10^3$$$.
Print $$$t$$$ lines, each containing one integer — the number of happy numbers in the given closed interval, modulo $$$10^9+7$$$.
47 75 101 10001 999999
1 2 143 143070
In the first range, $$$7$$$ is a happy number because $$$7^2=49$$$; $$$4^2+9^2=97$$$; $$$9^2+7^2=130$$$; $$$1^2+3^2+0^2=10$$$; $$$1^2+0^2=1$$$.
In the second range, the two happy numbers are $$$7, 10$$$.
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