CodeForces-124A-The number of positions

Description

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 Input

Input

3 1 1

Output

2

Input

5 2 3

Output

3

Hint

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.

水水水，判断一下就好了

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

int main()
{
int n, a, b, c, r;
while(scanf("%d%d%d", &n, &a, &b)!=EOF)
{
c = n-a-1;
if(c > b)
{
r = b+1;
}
else {
r = c+1;
}
printf("%d",r);
}
return 0;
}