import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a=sc.nextInt(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	}

} 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(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a=sc.nextInt(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	} main {
		Scanner sc = new Scanner(System.in);
		int a=sc.nextInt(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a=sc.nextInt() a sc.nextInt() sc.nextInt sc b=sc.nextInt() b sc.nextInt() sc.nextInt sc c=sc.nextInt(); c sc.nextInt() sc.nextInt sc sc.close() sc.close sc System.out.println((a<=b+c)?(b+c-a):0) System.out.println System.out System System.out (a<=b+c)?(b+c-a):0 (a<=b+c) a b+c b c (b+c-a) b+c b c a 0 String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a=sc.nextInt(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	}

} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a=sc.nextInt(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	}

} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a=sc.nextInt(),b=sc.nextInt(),c=sc.nextInt();
		sc.close();
		System.out.println((a<=b+c)?(b+c-a):0);
	}

}
