Problem:
Range Sum Query

Write a program which manipulates a sequence A = {a1, a2, . . . , an} with the following operations:

add(i, x): add x to ai.

getSum(s, t): print the sum of as, as+1,...,at.

Note that the initial values of ai (i = 1, 2, . . . , n) are 0.

Input

n q
com1 x1 y1
com2 x2 y2
...
comq xq yq

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, q queries are given where com represents the type of queries. '0' denotes add(xi, yi) and '1' denotes getSum(xi, yi).

Output

For each getSum operation, print the sum in a line.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

If comi is 0, then 1 ≤ xi ≤ n, 0 ≤ yi ≤ 1000.

If comi is 1, then 1 ≤ xi ≤ n, 1 ≤ yi ≤ n.

Sample Input 1

3 5
0 1 1
0 2 2
0 3 3
1 1 2
1 2 2

Sample Output 1

3
2

Solution in Python (judge verdict: Accepted)

class RangeSumQuery(object):

    def __init__(self, size):
        self.size = 1
        while self.size <= size:
            self.size *= 2
        self.data = [0] * (self.size*2-1)

    def add(self, idx, value):
        k = idx + self.size - 1
        self.data[k] += value
        while k > 0:
            k = (k - 1) / 2
            self.data[k] += value

    def get_sum(self, start, end):
        def query(k, left, right):
            if right <= start or end <= left:
                return 0
            if start <= left and right <= end:
                return self.data[k]
            vl = query(k*2+1, left, (left+right)/2)
            vr = query(k*2+2, (left+right)/2, right)
            return vl + vr
        return query(0, 0, self.size)


def main():
    n, q = map(int, raw_input().split())
    rsq = RangeSumQuery(n)
    for _ in xrange(q):
        com, x, y = map(int, raw_input().split())
        if com == 0:
            rsq.add(x, y)
        else:
            print rsq.get_sum(x, y+1)

if __name__ == "__main__":
    main()