package algo;

import java.util.Scanner;

//import algo.*;

public class sample7 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int X = sc.nextInt();
		int Y = sc.nextInt();
		int Z = sc.nextInt();
		int cnt = 0;
		for(int i=1; i <= Z; i++) {
			if(i == X) {
				
			}
			else if (i == Y) {
				
			}
			else {
				cnt++;
			}
		}
		System.out.println(cnt);
	}
}