import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		System.out.println(Math.max(0, C - (A - B)));
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

} import java.io.PrintWriter; PrintWriter java.io import java.util.ArrayList; ArrayList java.util import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		System.out.println(Math.max(0, C - (A - B)));
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

} Main public static void main(String[] args) {
		new Main().run();
	} main {
		new Main().run();
	} new Main().run() new Main().run new Main() String[] args args void run() {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		System.out.println(Math.max(0, C - (A - B)));
	} run {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		System.out.println(Math.max(0, C - (A - B)));
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) 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(0, C - (A - B))) System.out.println System.out System System.out Math.max(0, C - (A - B)) Math.max Math 0 C - (A - B) C (A - B) A B void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	} tr {
		System.out.println(Arrays.deepToString(objects));
	} System.out.println(Arrays.deepToString(objects)) System.out.println System.out System System.out Arrays.deepToString(objects) Arrays.deepToString Arrays objects Object... objects objects
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		System.out.println(Math.max(0, C - (A - B)));
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

}