import java.io.*;

/**
 * Created by Ayushi on 04/08/2019.
 */

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    }
} import java.io.*; io.* java public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    }
} Main public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    } main {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    } BufferedReader r = new BufferedReader(new InputStreamReader(System.in)); r new BufferedReader(new InputStreamReader(System.in)) String[] temp = r.readLine().split(" "); temp r.readLine().split(" ") r.readLine().split r.readLine() r.readLine r " " int a = Integer.parseInt(temp[0]); a Integer.parseInt(temp[0]) Integer.parseInt Integer temp[0] temp 0 int b = Integer.parseInt(temp[1]); b Integer.parseInt(temp[1]) Integer.parseInt Integer temp[1] temp 1 int c = Integer.parseInt(temp[2]); c Integer.parseInt(temp[2]) Integer.parseInt Integer temp[2] temp 2 r.close() r.close r System.out.println(Math.max(((b+c)-a), 0)) System.out.println System.out System System.out Math.max(((b+c)-a), 0) Math.max Math ((b+c)-a) (b+c) b c a 0 String[] args args public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    }
} public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    }
} Main
import java.io.*;

/**
 * Created by Ayushi on 04/08/2019.
 */

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String[] temp = r.readLine().split(" ");
        int a = Integer.parseInt(temp[0]);
        int b = Integer.parseInt(temp[1]);
        int c = Integer.parseInt(temp[2]);
        r.close();
        System.out.println(Math.max(((b+c)-a), 0));
    }
}
