Codeforces Beta Round #92 (Div. 2) / 124A The number of positions (简单数学)

A. The number of positions

http://codeforces.com/problemset/problem/124/A

time limit per test

0.5 second

memory limit per test

256 megabytes

input

standard input

output

standard output

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.

Sample test(s)

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.

/*30ms,0KB*/

#include<cstdio>
#include<algorithm>
using namespace std;

int main()
{
	int n, a, b;
	scanf("%d%d%d", &n, &a, &b);
	printf("%d", n - max(a + 1, n - b) + 1);
	return 0;
}