import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    } main {
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt())) System.out.println System.out System System.out Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()) Math.max Math 0 -sc.nextInt()+sc.nextInt()+sc.nextInt() -sc.nextInt()+sc.nextInt()+sc.nextInt() -sc.nextInt() sc.nextInt() sc.nextInt sc sc.nextInt() sc.nextInt sc sc.nextInt() sc.nextInt sc String[] args args public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.println(Math.max(0,-sc.nextInt()+sc.nextInt()+sc.nextInt()));
    }
}
