the number of position

Description
Jesse 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 less than B people standing behind him.

Find the number of different positions Jesse 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
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10 2 4
Sample Output
4

#include<iostream>using namespace std;int main(){    int num;    while(cin >> num){        int a, b;        cin >> a >> b ;        int result = num - a - b;        cout << result << endl;    }    return 0;}

we know that Jesse stands in line of people, and there are no less than A people standing in front of him, and no less than B people standing behind him.
so when there are exactly A and B in the problem, we can get the max.
then problem is solved