import java.util.Scanner;

public class Main {
    public static void debug(String str) {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    }

    public static void main(String[] args) {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void debug(String str) {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    }

    public static void main(String[] args) {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    }
} Main public static void debug(String str) {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    } debug {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    } boolean debug = false; debug false if (debug != false) {
            return;
        } debug != false debug false {
            return;
        } return; System.out.println(str) System.out.println System.out System System.out str String str str public static void main(String[] args) {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    } main {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    } long A; A long B; B long C; C try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        } {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        } Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) new Scanner(System.in) A = sc.nextLong() A sc.nextLong() sc.nextLong sc B = sc.nextLong() B sc.nextLong() sc.nextLong sc C = sc.nextLong() C sc.nextLong() sc.nextLong sc if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        } C < (A -B ) C (A -B ) A B {
            System.out.println(0);
        } System.out.println(0) System.out.println System.out System System.out 0 {
            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-B) A B return; String[] args args public class Main {
    public static void debug(String str) {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    }

    public static void main(String[] args) {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    }
} public class Main {
    public static void debug(String str) {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    }

    public static void main(String[] args) {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    }
} Main
import java.util.Scanner;

public class Main {
    public static void debug(String str) {
        boolean debug = false;
        if (debug != false) {
            return;
        }
        System.out.println(str);
    }

    public static void main(String[] args) {

        long A;
        long B;
        long C;

        try (Scanner sc = new Scanner(System.in)) {
            A = sc.nextLong();
            B = sc.nextLong();
            C = sc.nextLong();
        }
        if(C < (A -B )){
            System.out.println(0);
        }else{
            System.out.println(C -(A-B));
        }
        return;
    }
}
