import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		}
	}
} Main public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		}
	} main {
		try(Scanner sc = new Scanner(System.in)) {

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		}
	} try(Scanner sc = new Scanner(System.in)) {

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

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		} Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) 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 int capacity = a - b; capacity a - b a b if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			} c > capacity c capacity {
				System.out.println(c - capacity);
			} System.out.println(c - capacity) System.out.println System.out System System.out c - capacity c capacity {
				System.out.println(0);
			} System.out.println(0) System.out.println System.out System System.out 0 String[] args args public class Main {
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		}
	}
} public class Main {
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			int capacity = a - b;
			
			if ( c > capacity ) {
				System.out.println(c - capacity);
			}
			else {
				System.out.println(0);
			}
			
		}
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

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