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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	}
} 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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	}
} 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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	} 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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	} 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 int cap = a - b; cap a - b a b if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		} cap > c cap c {
			System.out.println(0);
		} System.out.println(0) System.out.println System.out System System.out 0 {
			System.out.println(c - cap);
		} System.out.println(c - cap) System.out.println System.out System System.out c - cap c cap sc.close() sc.close sc 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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	}
} 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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	}
} 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());
		int cap = a - b;
		if (cap > c) {
			System.out.println(0);
		} else {
			System.out.println(c - cap);
		}
		sc.close();
	}
}