import java.util.*;

public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 1000000007;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;

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

	public static void main(String[] args) {
		new Main().doIt();
	}
} import java.util.*; util.* java public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 1000000007;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;

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

	public static void main(String[] args) {
		new Main().doIt();
	}
} Main Scanner sc = new Scanner(System.in); sc new Scanner(System.in) final int MOD = 1000000007; MOD 1000000007 final int MAX = Integer.MAX_VALUE; MAX Integer.MAX_VALUE Integer Integer.MAX_VALUE final long LMAX = Long.MAX_VALUE; LMAX Long.MAX_VALUE Long Long.MAX_VALUE void doIt() {
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		System.out.println(Math.max(c - (a - b), 0));
	} doIt {
		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 public static void main(String[] args) {
		new Main().doIt();
	} main {
		new Main().doIt();
	} new Main().doIt() new Main().doIt new Main() String[] args args public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 1000000007;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;

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

	public static void main(String[] args) {
		new Main().doIt();
	}
} public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 1000000007;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;

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

	public static void main(String[] args) {
		new Main().doIt();
	}
} Main
import java.util.*;

public class Main {
	Scanner sc = new Scanner(System.in);
	final int MOD = 1000000007;
	final int MAX = Integer.MAX_VALUE;
	final long LMAX = Long.MAX_VALUE;

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

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