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 Ruby (judge verdict: Runtime Error)

n, q = gets.split.map(&:to_i)
a = [0] * (n+1)
sq = ((n+1)**0.5).to_i
sa = [0] * (sq+1)
q.times do
	com, x, y = gets.split.map(&:to_i)
	if com == 0
		a[x] += y
		sa[x/sq] += y
	else
		sum = 0
		if x/sq+1 >= y/sq
			x.upto(y) do |ai|
				sum += a[ai]
			end
		else
			x.upto(x/sq*sq-1) do |ai|
				sum += a[ai]
			end
			(x/sq+1).upto(y/sq-1) do |sai|
				sum += sa[sai]
			end
			(y/sq*sq).upto(y) do |ai|
				sum += a[ai]
			end
		end
		p sum
	end
end