import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  }
} import java.util.*; util.* java public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  } main {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a a b b c c answer; answer a = Integer.parseInt(sc.next()) a Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc b = Integer.parseInt(sc.next()) b Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc c = Integer.parseInt(sc.next()) c Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc if(a - b >= c) answer = 0;
    else answer = c - (a - b); a - b >= c a - b a b c answer = 0 answer 0 answer = c - (a - b) answer c - (a - b) c (a - b) a b System.out.println(answer) System.out.println System.out System System.out answer String[] args args public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  }
} public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  }
} Main
import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, b, c, answer;
    a = Integer.parseInt(sc.next());
    b = Integer.parseInt(sc.next());
    c = Integer.parseInt(sc.next());
    if(a - b >= c) answer = 0;
    else answer = c - (a - b);
    System.out.println(answer);
  }
}
