C. Little Girl and Maximum Sumtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputThe little girl loves the problems on array queries very much.One day she came across a rather well-known problem: you've got an array of n elements (the elements of the array are indexed starting from 1); also, there are q queries, each one is defined by a pair of integers l_i, r_i (1 \le l_i \le r_i \le n). You need to find for each query the sum of elements of the array with indexes from l_i to r_i, inclusive.The little girl found the problem rather boring. She decided to reorder the array elements before replying to the queries in a way that makes the sum of query replies maximum possible. Your task is to find the value of this maximum sum.InputThe first line contains two space-separated integers n (1 \le n \le 2\cdot10^5) and q (1 \le q \le 2\cdot10^5) — the number of elements in the array and the number of queries, correspondingly.The next line contains n space-separated integers a_i (1 \le a_i \le 2\cdot10^5) — the array elements.Each of the following q lines contains two space-separated integers l_i and r_i (1 \le l_i \le r_i \le n) — the i-th query.OutputIn a single line print, a single integer — the maximum sum of query replies after the array elements are reordered.Please, do not use the %lld specifier to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams or the %I64d specifier.ExamplesInput3 35 3 21 22 31 3Output25Input5 35 2 4 1 31 52 32 3Output33
Input3 35 3 21 22 31 3
Output25
['data structures', 'greedy', 'implementation', 'sortings', '*1500']