Дерево Фенвика

Dima and large array

Mother gave Dima as a present an array of length n. The array is not simple, but special. Dima can choose two numbers i and d (1in, -1000d1000), and from the element with index i magically add d. Dima plays with his array, and mother gives his questions time from time - what is the sum of all the numbers in array with indexes from f to t inclusive? However, the mother is very busy and can not ask questions as often as usual - all she asked no more than 1000 questions. Dima easily managed this problem, but what about you?


The first line contains two integers n and q (1n106, 1q5 ·105) - the number of elements in array and the total number of operations. In the next line n numbers are given: a1, a2, ..., an (-1000ai1000) - the initial state of array. The next q lines contain the operations and queries. The first character in the line can be either + or ?. If the line starts with +, this is an assignment operation. Next values are i and d, their restrictions are given earlier. If the line starts with ?, this is a query. Then go numbers f and t (1f, tn).


For each query print on a separate line the sum of the numbers in array with indexes from f to t inclusive.

Time limit 7 seconds
Memory limit 256 MiB
Input example #1
3 3
1 2 3
? 1 3
+ 3 -1
? 1 3
Output example #1
Author Egor Kulikov
Source Winter School Kharkov 2012