CF1539B.Love Song

Petya once wrote a sad love song and shared it to Vasya. The song is a string consisting of lowercase English letters. Vasya made up $q$ questions about this song. Each question is about a subsegment of the song starting from the $l$-th letter to the $r$-th letter. Vasya considers a substring made up from characters on this segment and repeats each letter in the subsegment $k$ times, where $k$ is the index of the corresponding letter in the alphabet. For example, if the question is about the substring "abbcb", then Vasya repeats letter 'a' once, each of the letters 'b' twice, letter 'c" three times, so that the resulting string is "abbbbcccbb", its length is $10$. Vasya is interested about the length of the resulting string.

Help Petya find the length of each string obtained by Vasya.

佩佳曾写过一首忧伤的爱情歌曲，并将其分享给了瓦夏。这首歌是一个由小写英文字母组成的字符串。瓦夏围绕这首歌提出了 $q$ 个问题。每个问题均针对歌曲的一个子段，即从第 $l$ 个字母到第 $r$ 个字母（含端点）。瓦夏考虑该子段中构成的子串，并将子段中每个字母重复 $k$ 次，其中 $k$ 为该字母在英文字母表中的位置（即 'a' 对应 $1$，'b' 对应 $2$，……，'z' 对应 $26$）。例如，若问题涉及子串 "abbcb"，则瓦夏将字母 'a' 重复 $1$ 次，每个字母 'b' 重复 $2$ 次，字母 'c' 重复 $3$ 次，从而得到字符串 "abbbbcccbb"，其长度为 $10$。瓦夏关心的是所得字符串的长度。

请帮助佩佳计算瓦夏对每个子段所生成的字符串的长度。

The first line contains two integers $n$ and $q$ ($1\leq n\leq 100\,000$, $1\leq q \leq 100\,000$) — the length of the song and the number of questions.

The second line contains one string $s$ — the song, consisting of $n$ lowercase letters of English letters.

Vasya's questions are contained in the next $q$ lines. Each line contains two integers $l$ and $r$ ($1 \leq l \leq r \leq n$) — the bounds of the question.

第一行包含两个整数 $n$ 和 $q$（$1\leq n\leq 100\,000$，$1\leq q \leq 100\,000$）—— 分别表示歌曲的长度和问题的数量。

第二行包含一个字符串 $s$ —— 表示歌曲，由 $n$ 个小写英文字母组成。

瓦西娅的问题包含在接下来的 $q$ 行中。每行包含两个整数 $l$ 和 $r$（$1 \leq l \leq r \leq n$）—— 表示该问题的查询区间边界。

Print $q$ lines: for each question print the length of the string obtained by Vasya.

输出 $q$ 行：对每个询问，输出 Vasya 得到的字符串的长度。

In the first example Vasya is interested in three questions. In the first question Vasya considers the substring "aba", that transforms to "abba", so the answer is equal to $4$. In the second question Vasya considers "baca", that transforms to "bbaccca", so the answer is $7$. In the third question Vasya considers the string "abacaba",that transforms to "abbacccabba" of length $11$.

在第一个样例中，Vasya 关注三个问题。第一个问题中，Vasya 考虑子串 “aba”，它变换为 “abba”，因此答案为 $4$。第二个问题中，Vasya 考虑 “baca”，它变换为 “bbaccca”，因此答案为 $7$。第三个问题中，Vasya 考虑字符串 “abacaba”，它变换为长度为 $11$ 的字符串 “abbacccabba”。