Score : $100$ points
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."
Input is given from Standard Input in the following format:
Print the answer.
The second car from the front of a $4$-car train is the third car from the back.