import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	} main {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	} 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 sc.close() sc.close sc int r = A - (B + C); r A - (B + C) A (B + C) B C System.out.println(r > 0 ? 0 : r * -1) System.out.println System.out System System.out r > 0 ? 0 : r * -1 r > 0 r 0 0 r * -1 r -1 1 String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		sc.close();
		int r = A - (B + C);
		System.out.println(r > 0 ? 0 : r * -1);
	}
}