Problem:
Score : 100 points

Problem Statement

There is an N-car train.

You are given an integer i. Find the value of j such that the following statement is true: "the i-th car from the front of the train is the j-th car from the back."

Constraints

1 \leq N \leq 100

1 \leq i \leq N

Input

Input is given from Standard Input in the following format:

N i

Output

Print the answer.

Sample Input 1

4 2

Sample Output 1

3

The second car from the front of a 4-car train is the third car from the back.

Sample Input 2

1 1

Sample Output 2

1

Sample Input 3

15 11

Sample Output 3

5

Solution in Python (3.4.3) (judge verdict: Runtime Error)

n=int(input())
nums=[int(x) for x in input().split()]

def findMedian(nums):
    size=len(nums)
    mIndex = (size*(size+1)//2) + 1
    gap=0
    mValue=0
    while mIndex>0 and gap<size:
        start=0
        end=start+gap
        while end<size and mIndex>0:
            mIndex-=1
            mValue=nums[(start+end+1)//2]
            start+=1
            end+=1
        gap+=1
    return mValue

print(findMedian(nums))