import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	}

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

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	}

} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	} main {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) final int A = scan.nextInt(); A scan.nextInt() scan.nextInt scan final int B = scan.nextInt(); B scan.nextInt() scan.nextInt scan final int C = scan.nextInt(); C scan.nextInt() scan.nextInt scan scan.close() scan.close scan int remain1 = A - B; remain1 A - B A B if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		} remain1 > C remain1 C {
			System.out.println(0);
		} System.out.println(0) System.out.println System.out System System.out 0 {
			System.out.println(C - remain1);
		} System.out.println(C - remain1) System.out.println System.out System System.out C - remain1 C remain1 String[] args args public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	}

} public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int A = scan.nextInt();
		final int B = scan.nextInt();
		final int C = scan.nextInt();
		scan.close();

		int remain1 = A - B;

		if (remain1 > C) {
			System.out.println(0);
		} else {
			System.out.println(C - remain1);
		}

	}

}
