import java.util.*;

public class Main{
  public static void main(String args[]){
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String args[]){
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  }
} Main public static void main(String args[]){
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  } main {
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int A = scanner.nextInt(); A scanner.nextInt() scanner.nextInt scanner int B = scanner.nextInt(); B scanner.nextInt() scanner.nextInt scanner int C = scanner.nextInt(); C scanner.nextInt() scanner.nextInt scanner int result = 0; result 0 int amount = A - (B + C); amount A - (B + C) A (B + C) B C if(amount < 0){
      result = (B + C) - A;
    } amount < 0 amount 0 {
      result = (B + C) - A;
    } result = (B + C) - A result (B + C) - A (B + C) B C A System.out.println(result) System.out.println System.out System System.out result String args[] args public class Main{
  public static void main(String args[]){
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  }
} public class Main{
  public static void main(String args[]){
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  }
} Main
import java.util.*;

public class Main{
  public static void main(String args[]){
    Scanner scanner = new Scanner(System.in);
    int A = scanner.nextInt();
    int B = scanner.nextInt();
    int C = scanner.nextInt();
    
    int result = 0;
    int amount = A - (B + C);
    if(amount < 0){
      result = (B + C) - A;
    }
    
    System.out.println(result);
  }
}
