N. No Distance is Too Far Apart
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Alice and Bob are standing somewhere in a vaccination queue of $$$N$$$ people (including themselves). With everyone wearing facemasks and keeping their distance, it's almost impossible to recognize anyone else.

Alice counts $$$A$$$ people standing in front of her, while Bob counts $$$B$$$ people standing behind him.

Even if they can't see each other, they still want to know how far apart they are. Can you help them find out how many people are standing between Alice and Bob (excluding both of them)?

Input

One line contains three integers $$$N$$$, $$$A$$$, and $$$B$$$ $$$(2 \le N \le 1000, 0 \le A,B \le N-1; A+B \neq N-1)$$$ — the number of people in the queue, the number of people in front of Alice, and the number of people behind Bob, respectively.

Output

Output a single integer — the number of people standing between Alice and Bob.

Examples
Input
10 2 3
Output
3
Input
7 4 5
Output
2
Input
998 244 353
Output
399
Note

In the first example, the line, from front to back, can be described as ooAoooBooo where A is where Alice is and B is where Bob is.

In the second example, the line, from front to back, can be described as oBooAoo where A is where Alice is and B is where Bob is.