import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	}

} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	}

} Main public static void main(String[] args) {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	} main {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int A = scan.nextInt(); A scan.nextInt() scan.nextInt scan int B = scan.nextInt(); B scan.nextInt() scan.nextInt scan int C = scan.nextInt(); C scan.nextInt() scan.nextInt scan int rest; rest if(B+C < A) {rest =0;}
    else rest = B+C-A; B+C < A B+C B C A {rest =0;} rest =0 rest 0 rest = B+C-A rest B+C-A B+C B C A System.out.println(rest) System.out.println System.out System System.out rest String[] args args public class Main {
	public static void main(String[] args) {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	}

} public class Main {
	public static void main(String[] args) {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	}

} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    int C = scan.nextInt();
    
    int rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	}

}
