import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    }

    private void solveD(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    }

    private void solveE(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    }

    private void solveC(Scanner sc) {

    }

    void solveB(Scanner sc) {

    }

    class SolveB {
    }

    class Edge {
    }

    void solveA(Scanner sc) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    }

    private void solveD(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    }

    private void solveE(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    }

    private void solveC(Scanner sc) {

    }

    void solveB(Scanner sc) {

    }

    class SolveB {
    }

    class Edge {
    }

    void solveA(Scanner sc) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    }
} Main public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    } main {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    } try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        } {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        } Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) new Scanner(System.in) Main main = new Main(); main new Main() main.solveA(sc) main.solveA main sc String[] args args private void solveD(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    } solveD {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    } try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        } catch (IOException e) {

        } IOException e {

        } {} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) new BufferedReader(new InputStreamReader(System.in)) PrintWriter pw = new PrintWriter(System.out) PrintWriter pw = new PrintWriter(System.out) new PrintWriter(System.out) Scanner sc sc private void solveE(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    } solveE {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    } try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        } catch (IOException e) {

        } IOException e {

        } {

        } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) new BufferedReader(new InputStreamReader(System.in)) PrintWriter pw = new PrintWriter(System.out) PrintWriter pw = new PrintWriter(System.out) new PrintWriter(System.out) Scanner sc sc private void solveC(Scanner sc) {

    } solveC {

    } Scanner sc sc void solveB(Scanner sc) {

    } solveB {

    } Scanner sc sc void solveA(Scanner sc) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    } solveA {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    } int a = sc.nextInt(); a sc.nextInt() sc.nextInt sc int b = sc.nextInt(); b sc.nextInt() sc.nextInt sc int c = sc.nextInt(); c sc.nextInt() sc.nextInt sc System.out.println(Math.max(c - (a - b), 0)) System.out.println System.out System System.out Math.max(c - (a - b), 0) Math.max Math c - (a - b) c (a - b) a b 0 Scanner sc sc class SolveB {
    } SolveB class Edge {
    } Edge public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    }

    private void solveD(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    }

    private void solveE(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    }

    private void solveC(Scanner sc) {

    }

    void solveB(Scanner sc) {

    }

    class SolveB {
    }

    class Edge {
    }

    void solveA(Scanner sc) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    }
} public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    }

    private void solveD(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    }

    private void solveE(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    }

    private void solveC(Scanner sc) {

    }

    void solveB(Scanner sc) {

    }

    class SolveB {
    }

    class Edge {
    }

    void solveA(Scanner sc) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            Main main = new Main();

            main.solveA(sc);
            // main.solveB(sc);
            // main.solveC(sc);
            // main.solveD(sc);
            // main.solveE(sc);

        }

    }

    private void solveD(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {} catch (IOException e) {

        }
    }

    private void solveE(Scanner sc) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter pw = new PrintWriter(System.out)) {

        } catch (IOException e) {

        }
    }

    private void solveC(Scanner sc) {

    }

    void solveB(Scanner sc) {

    }

    class SolveB {
    }

    class Edge {
    }

    void solveA(Scanner sc) {
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        System.out.println(Math.max(c - (a - b), 0));

    }
}
