Line of People

You are given integers n, a and b. You are standing in a line of n people. You don’t know which position you’re in, but you know there are at least a people in front of you and at most b people behind you.

Return the number of possible positions you could be in.

https://binarysearch.com/problems/Line-of-People

Examples

Example 1

Input

• n = 10
• a = 3
• b = 4

Output

• answer = 5

Explanation

There’s 10 people and at least 3 are in front and at most 4 are behind.

This means you can be in indexes [0, 1, 2, 3, 4]. For example, at index 0, 9 people are in front, 0 are behind.

Solution