import java.util.Scanner;

public class Main {

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

	}

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

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

	}

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int A = Integer.parseInt(sc.next()); A Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int B = Integer.parseInt(sc.next()); B Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int C = Integer.parseInt(sc.next()); C Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		} A - B >= C A - B A B C {
			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 String[] args args public class Main {

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

	}

} public class Main {

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

	}

} Main
import java.util.Scanner;

public class Main {

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

		int A = Integer.parseInt(sc.next());
		int B = Integer.parseInt(sc.next());
		int C = Integer.parseInt(sc.next());

		if (A - B >= C ) {
			System.out.println("0");
		} else {
			System.out.println(C-(A-B));
		}

	}

}
