human
I found an interesting problem on https://codeforces.com/problemset/problem/1189/C:
Consider a sequence of digits of length $2^k$ $[a_1, a_2, \ldots, a_{2^k}]$. We perform the following operation with it: replace pairs $(a_{2i+1}, a_{2i+2})$ with $(a_{2i+1} + a_{2i+2})\bmod 10$ for $0\le i<2^{k-1}$. For every $i$ where $a_{2i+1} + a_{2i+2}\ge 10$ we get a candy! As a result, we will get a sequence of length $2^{k-1}$.

Less formally, we partition sequence of length $2^k$ into $2^{k-1}$ pairs, each consisting of 2 numbers: the first pair consists of the first and second numbers, the second of the third and fourth $\ldots$, the last pair consists of the ($2^k-1$)-th and ($2^k$)-th numbers. For every pair such that sum of numbers in it is at least $10$, we get a candy. After that, we replace every pair of numbers with a remainder of the division of their sum by $10$ (and don't change the order of the numbers).

Perform this operation with a resulting array until it becomes of length $1$. Let $f([a_1, a_2, \ldots, a_{2^k}])$ denote the number of candies we get in this process. 

For example: if the starting sequence is $[8, 7, 3, 1, 7, 0, 9, 4]$ then:

After the first operation the sequence becomes $[(8 + 7)\bmod 10, (3 + 1)\bmod 10, (7 + 0)\bmod 10, (9 + 4)\bmod 10]$ $=$ $[5, 4, 7, 3]$, and we get $2$ candies as $8 + 7 \ge 10$ and $9 + 4 \ge 10$.

After the second operation the sequence becomes $[(5 + 4)\bmod 10, (7 + 3)\bmod 10]$ $=$ $[9, 0]$, and we get one more candy as $7 + 3 \ge 10$. 

After the final operation sequence becomes $[(9 + 0) \bmod 10]$ $=$ $[9]$. 

Therefore, $f([8, 7, 3, 1, 7, 0, 9, 4]) = 3$ as we got $3$ candies in total.

You are given a sequence of digits of length $n$ $s_1, s_2, \ldots s_n$. You have to answer $q$ queries of the form $(l_i, r_i)$, where for $i$-th query you have to output $f([s_{l_i}, s_{l_i+1}, \ldots, s_{r_i}])$. It is guaranteed that $r_i-l_i+1$ is of form $2^k$ for some nonnegative integer $k$.

-----Input-----

The first line contains a single integer $n$ ($1 \le n \le 10^5$) — the length of the sequence.

The second line contains $n$ digits $s_1,...

I tried it in Python, but could not do it. Can you solve it?

Can you provide a the Python code you requested?
assistant
#Here is the Python code you requested.

# @author 

import sys

class CCandies:
    def solve(self):
        n = int(input())
        s = [int(_) for _ in input().split()]
        q = int(input())
        pre = [0] * (n + 1)
        for i in range(1, n + 1):
            pre[i] = pre[i - 1] + s[i - 1]
        for i in range(q):
            li, ri = [int(_) for _ in input().split()]
            print((pre[ri] - pre[li - 1]) // 10)

solver = CCandies()
input = sys.stdin.readline

solver.solve()