Algorithm

problem link- https://www.spoj.com/problems/PRADIPSUM/

PRADIPSUM - Easy Math

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Zoro is a student of a primary school. He likes to solve mathematical problem. One day he tries to solve a math, but he is unable to solve the problem efficiently because of being a student of primary school. As you are a programmer he wants your help to solve this problem. The problem is to find the sum of some consecutive numbers.

Example, if the first number is 2 and the last number is 5, then the result would be

2 + 3 + 4 + 5 = 14

Input

Every line contains two integers a and b. Input is terminated by the end of file.

Output

Output the sum the of all numbers between a and b (inclusively).

Constraints

-108  ≤ (a , b) ≤ 108

Example

Input:
2 5
5 10

Output:
14
45

 

Code Examples

#1 Code Example with Python Programming

Code - Python Programming

def sum(x):
    if x < 0:
        return -(-x * (-x + 1) // 2)
    else:
        return x * (x + 1) // 2

while True:
    try:
        a, b = map(int, input().split())
        if a > b:
            a, b = b, a
        if b < 0:
            print(sum(a) - sum(b + 1))
        elif a <= 0:
            print(sum(b) + sum(a))
        else:
            print(sum(b) - sum(a - 1))
    except EOFError:
        exit(0)
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Input

x
–
+
cmd
2 5
5 10

Output

x
–
+
cmd
14
45
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