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-----
4 2

-----Sample Output-----
3

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

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