import java.util.*;
public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  }
} import java.util.*; util.* java public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  }
} Main public static void main(String[]args){
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  } main {
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int A = sc.nextInt(); A sc.nextInt() sc.nextInt sc int B = sc.nextInt(); B sc.nextInt() sc.nextInt sc int C = sc.nextInt(); C sc.nextInt() sc.nextInt sc int w = A-B-C; w A-B-C A-B-C A B C if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      } A>=B+C A B+C B C {
        System.out.print(0);
      } System.out.print(0) System.out.print System.out System System.out 0 {
        System.out.print(Math.abs(w));
      } System.out.print(Math.abs(w)) System.out.print System.out System System.out Math.abs(w) Math.abs Math w String[]args args public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  }
} public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  }
} Main
import java.util.*;
public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);


      int A = sc.nextInt();
      int B = sc.nextInt();
      int C = sc.nextInt();


      int w = A-B-C;

      if(A>=B+C){
        System.out.print(0);
      }else{
        System.out.print(Math.abs(w));
      }

  }
}
