Reverse

题号：NC52807
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
Special Judge, 64bit IO Format: %lld

题目描述

Bobo has a n digits decimal number $D = d_1d_2\dots d_n$ (It may have leading zeros).
Let R(i, j) denotes number D with digits between the i-th position and j-th position reversed. That is, $R(i, j) = d_1\dots d_{i - 1} d_jd_{j - 1}\dots d_i d_{j + 1}d_{j + 2}\dots d_n$ .
Bobo would like to find $\sum_{i = 1}^n \sum_{j = i}^n R(i, j)$ modulo $(10^9+7)$ .

输入描述:

The input contains at most 30 sets. For each set:
The first line contains an integer n ().
The second line contains n digits  .

输出描述:

For each set, an integer denotes the result

示例1

输入

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2
12

输出

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示例2

输入

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3
012

输出

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示例3

输入

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10
0123456789

输出

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733424314