import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    }

} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    }

} Main public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    } main {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    } Scanner in = new Scanner(System.in); in new Scanner(System.in) String[] params = in.nextLine().split(" "); params in.nextLine().split(" ") in.nextLine().split in.nextLine() in.nextLine in " " int a = Integer.parseInt(params[0]); a Integer.parseInt(params[0]) Integer.parseInt Integer params[0] params 0 int b = Integer.parseInt(params[1]); b Integer.parseInt(params[1]) Integer.parseInt Integer params[1] params 1 int c = Integer.parseInt(params[2]); c Integer.parseInt(params[2]) Integer.parseInt Integer params[2] params 2 if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        } a < b + c a b + c b c {
            System.out.println( c - a + b );
        } System.out.println( c - a + b ) System.out.println System.out System System.out c - a + b c - a c a b {
            System.out.println( 0 );
        } System.out.println( 0 ) System.out.println System.out System System.out 0 String[] args args public class Main {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    }

} public class Main {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    }

} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String[] params = in.nextLine().split(" ");
        int a = Integer.parseInt(params[0]);
        int b = Integer.parseInt(params[1]);
        int c = Integer.parseInt(params[2]);

        if( a < b + c ){
            System.out.println( c - a + b );
        }
        else {
            System.out.println( 0 );
        }

    }

}