import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        }

    } import java.util.*; util.* java public class Main {

    public static void main(String[] args) {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        }

    } Main public static void main(String[] args) {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        } main {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        } Scanner yomi = new Scanner(System.in); yomi new Scanner(System.in) int a = yomi.nextInt(); a yomi.nextInt() yomi.nextInt yomi int b = yomi.nextInt(); b yomi.nextInt() yomi.nextInt yomi int c = yomi.nextInt(); c yomi.nextInt() yomi.nextInt yomi int d = a-b; d a-b a b if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d); d>=c d c {
            System.out.println(0);
            } System.out.println(0) System.out.println System.out System System.out 0 System.out.println(c-d) System.out.println System.out System System.out c-d c d String[] args args public class Main {

    public static void main(String[] args) {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        }

    } public class Main {

    public static void main(String[] args) {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        }

    } Main
import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner yomi = new Scanner(System.in);
        int a = yomi.nextInt();
        int b = yomi.nextInt();
        int c = yomi.nextInt();
        int d = a-b;
        if (d>=c){
            System.out.println(0);
            }else System.out.println(c-d);
        }

    }