"""# ### 谜题描述 This is the easy version of the problem. The only difference is that in this version q = 1. You can make hacks only if both versions of the problem are solved. There is a process that takes place on arrays a and b of length n and length n-1 respectively. The process is an infinite sequence of operations. Each operation is as follows: * First, choose a random integer i (1 ≤ i ≤ n-1). * Then, simultaneously set a_i = min\left(a_i, \frac{a_i+a_{i+1}-b_i}{2}\right) and a_{i+1} = max\left(a_{i+1}, \frac{a_i+a_{i+1}+b_i}{2}\right) without any rounding (so values may become non-integer). See notes for an example of an operation. It can be proven that array a converges, i. e. for each i there exists a limit a_i converges to. Let function F(a, b) return the value a_1 converges to after a process on a and b. You are given array b, but not array a. However, you are given a third array c. Array a is good if it contains only integers and satisfies 0 ≤ a_i ≤ c_i for 1 ≤ i ≤ n. Your task is to count the number of good arrays a where F(a, b) ≥ x for q values of x. Since the number of arrays can be very large, print it modulo 10^9+7. Input The first line contains a single integer n (2 ≤ n ≤ 100). The second line contains n integers c_1, c_2 …, c_n (0 ≤ c_i ≤ 100). The third line contains n-1 integers b_1, b_2, …, b_{n-1} (0 ≤ b_i ≤ 100). The fourth line contains a single integer q (q=1). The fifth line contains q space separated integers x_1, x_2, …, x_q (-10^5 ≤ x_i ≤ 10^5). Output Output q integers, where the i-th integer is the answer to the i-th query, i. e. the number of good arrays a where F(a, b) ≥ x_i modulo 10^9+7. Example Input 3 2 3 4 2 1 1 -1 Output 56 Note The following explanation assumes b = [2, 1] and c=[2, 3, 4] (as in the sample). Examples of arrays a that are not good: * a = [3, 2, 3] is not good because a_1 > c_1; * a = [0, -1, 3] is not good because a_2 < 0. One possible good array a is [0, 2, 4]. We can show that no operation has any effect on this array, so F(a, b) = a_1 = 0. Another possible good array a is [0, 1, 4]. In a single operation with i = 1, we set a_1 = min((0+1-2)/(2), 0) and a_2 = max((0+1+2)/(2), 1). So, after a single operation with i = 1, a becomes equal to [-1/2, 3/2, 4]. We can show that no operation has any effect on this array, so F(a, b) = -1/2. Here is a reference code to solve this task. You can use this to help you genereate cases or validate the solution. ```python from __future__ import division,print_function from heapq import* import sys le = sys.__stdin__.read().split(\"\n\")[::-1] mo=10**9+7 if 1: n=int(le.pop()) c = list(map(int,le.pop().split())) b = list(map(int,le.pop().split())) le.pop() x=int(le.pop()) prefb=[b[0]] for k in b[1:]: prefb.append(k+prefb[-1]) prefb.append(0) #careful when going to C prefbt=[0] for k in range(1,n-1): prefbt.append(k*b[k]+prefbt[-1]) prefbt.append(0) sc=sum(c) d=[[0]*(sc+1) for k in range(n+1)]#fuck a lot of prefix sum in this problem ds=[[0]*(sc+2) for k in range(n+1)]#prefix array beginning with 0 ds[-1]=list(range(sc+2)) d[-1]=[1]*(sc+1) for index in range(n-1,-1,-1): #can even go linearly for minpref minpref=0 while (minpref-index*prefb[index-1]+prefbt[index-1])/(index+1)= 1: denominator = index + 1 numerator = minpref - index * prefb[index-1] + (prefbt[index-1] if (index-1) < len(prefbt) else 0) while denominator != 0 and numerator / denominator < x_val: minpref += 1 numerator = minpref - index * prefb[index-1] + (prefbt[index-1] if (index-1) < len(prefbt) else 0) else: denominator = index + 1 numerator = minpref - 0 * prefb[-1] + (prefbt[-1] if prefbt else 0) while denominator != 0 and numerator / denominator < x_val: minpref += 1 numerator = minpref - 0 * prefb[-1] + (prefbt[-1] if prefbt else 0) for pref in range(sc+1): mi = min(pref + c[index] + 1, sc+1) ma = max(minpref, pref) if mi < ma: d[index][pref] = 0 else: d[index][pref] = (ds[index+1][mi] - ds[index+1][ma]) % MOD for pref in range(1, sc+2): ds[index][pref] = (ds[index][pref-1] + d[index][pref-1]) % MOD return d[0][0] % MOD