import 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 = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    }
} import java.util.*; util.* java 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 = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    }
} 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 = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    } main {
    	Scanner scan = new Scanner(System.in);
      	int a = scan.nextInt();
      	int b = scan.nextInt();
      	int c = scan.nextInt();
      	int rest = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    } 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 = a - b; rest a - b a b if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        } c -rest > 0 c -rest c rest 0 {
        	System.out.print(c - rest);
        } System.out.print(c - rest) System.out.print System.out System System.out c - rest c rest {
        	System.out.print("0");
        } System.out.print("0") System.out.print System.out System System.out "0" 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 = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    }
} 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 = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    }
} Main
import 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 = a - b;
      	if(c -rest > 0){
        	System.out.print(c - rest);
        }
      	else{
        	System.out.print("0");
        }
    }
}