Petr stands in line of n people, but he doesn't know exactly which position he occupies. He can say that there are no less than a people standing in front of him and no more than b people standing behind him. Find the number of different positions Petr can occupy.

Input

The only line contains three integers n, a and b (0 ≤ a, b < n ≤ 100).

Output

Print the single number — the number of the sought positions.

Examples

Input

3 1 1


Output

2


Input

5 2 3


Output

3

Note

The possible positions in the first sample are: 2 and 3 (if we number the positions starting with 1).

In the second sample they are 3, 4 and 5.
import java.util.*;
import java.util.stream.Collectors;

public class Solution {
    private static Scanner in = new Scanner(System.in);

    public static void main(String[] args) {
        var input = Arrays.stream(in.nextLine().split(" ")).map(Integer::parseInt)
                .collect(Collectors.toList());

        int total = input.get(0);
        int remain = total - input.get(1);
        System.out.println(Math.min(remain,input.get(2)+1));
    }
}
