import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    } main {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) Integer A = scan.nextInt(); A scan.nextInt() scan.nextInt scan Integer B = scan.nextInt(); B scan.nextInt() scan.nextInt scan Integer C = scan.nextInt(); C scan.nextInt() scan.nextInt scan Integer answer = 0; answer 0 if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        } A-B < C A-B A B C {
            answer = C-A+B;
        } answer = C-A+B answer C-A+B C-A C A B {
            answer = 0;
        } answer = 0 answer 0 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) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer A = scan.nextInt();
        Integer B = scan.nextInt();
        Integer C = scan.nextInt();
        Integer answer = 0;
        if(A-B < C) {
            answer = C-A+B;
        }
        else {
            answer = 0;
        }
        System.out.println(answer);
    }
}