B"You are given two integer arrays a and b ( b_i neq 0 and |b_i| <= q 10^9 ). Array a is sorted in non-decreasing order. The cost of a subarray a[l:r] is defined as follows: If sum limits_{j = l}^{r} b_j neq 0 , then the cost is not defined. Otherwise: You are given q queries in the form of two integers l and r . You have to compute the cost of subarray a[l:r] for each query, modulo 10^9 + 7 . If you don't know what the minimum cost of maximum flow means, read here. The first line of input contains two integers n and q (2 <= q n <= q 2 cdot 10^5, 1 <= q q <= q 2 cdot10^5) -- length of arrays a , b and the number of queries. The next line contains n integers a_1,a_2 ldots a_n ( 0 <= q a_1 <= a_2 ldots <= a_n <= q 10^9) -- the array a . It is guaranteed that a is sorted in non-decreasing order. The next line contains n integers b_1,b_2 ldots b_n (-10^9 <= q b_i <= q 10^9, b_i neq 0) -- the array b . The i -th of the next q lines contains two integers l_i,r_i (1 <= q l_i <= q r_i <= q n) . It is guaranteed that sum limits_{j = l_i}^{r_i} b_j = 0 . For each query l_i , r_i -- print the cost of subarray a[l_i:r_i] modulo 10^9 + 7 . In the first query, the maximum possible flow is 1 i.e one unit from source to 2 , then one unit from 2 to 3 , then one unit from 3 to sink. The cost of the flow is 0 cdot 1 + |2 - 4| cdot 1 + 0 cdot 1 = 2 . In the second query, the maximum possible flow is again 1 i.e from source to 7 , 7 to 6 , and 6 to sink with a cost of 0 cdot |10 - 10| cdot 1 + 0 cdot 1 = 0 . In the third query, the flow network is shown on the left with capacity written over the edge and the cost written in bracket. The image on the right shows the flow through each edge in an"...