import java.util.*;
import java.io.*;

class Main {

	void solve () {

		int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
		out.println(Math.max(0,c-(a-b)));
		
	}

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

} import java.util.*; util.* java import java.io.*; io.* java class Main {

	void solve () {

		int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
		out.println(Math.max(0,c-(a-b)));
		
	}

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

} Main public static PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) public static Scanner in = new Scanner(System.in); in new Scanner(System.in) void solve () {

		int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
		out.println(Math.max(0,c-(a-b)));
		
	} solve {

		int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
		out.println(Math.max(0,c-(a-b)));
		
	} int a = in.nextInt() a in.nextInt() in.nextInt in b = in.nextInt() b in.nextInt() in.nextInt in c = in.nextInt(); c in.nextInt() in.nextInt in out.println(Math.max(0,c-(a-b))) out.println out Math.max(0,c-(a-b)) Math.max Math 0 c-(a-b) c (a-b) a b public static void main(String[] args) {
		new Main().solve();
		out.flush();
	} main {
		new Main().solve();
		out.flush();
	} new Main().solve() new Main().solve new Main() out.flush() out.flush out String[] args args
import java.util.*;
import java.io.*;

class Main {

	void solve () {

		int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
		out.println(Math.max(0,c-(a-b)));
		
	}

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

}