import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	}
	} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	}
	} Main public static void main(String[] args) {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	} main {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	} Scanner t=new Scanner(System.in); t new Scanner(System.in) int a=t.nextInt() a t.nextInt() t.nextInt t b=t.nextInt() b t.nextInt() t.nextInt t c=t.nextInt(); c t.nextInt() t.nextInt t while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			} a != b && c !=0 a != b a b c !=0 c 0 {
			b = b +1;
			c = c-1;
			} b = b +1 b b +1 b 1 c = c-1 c c-1 c 1 System.out.println(c) System.out.println System.out System System.out c String[] args args public class Main {

	public static void main(String[] args) {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	}
	} public class Main {

	public static void main(String[] args) {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	}
	} Main
import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner t=new Scanner(System.in);
		int a=t.nextInt(), b=t.nextInt(), c=t.nextInt();
		while(a != b && c !=0) {
			b = b +1;
			c = c-1;
			}
		System.out.println(c);
		
	}
	}