import java.util.Scanner;

public class Main{
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	}
} Main public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	} main {
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int capacityOfA = scan.nextInt(); capacityOfA scan.nextInt() scan.nextInt scan int waterInA = scan.nextInt(); waterInA scan.nextInt() scan.nextInt scan int waterInB= scan.nextInt(); waterInB scan.nextInt() scan.nextInt scan int printNum = waterInB - (capacityOfA - waterInA); printNum waterInB - (capacityOfA - waterInA) waterInB (capacityOfA - waterInA) capacityOfA waterInA if(printNum < 0){
			printNum = 0;
		} printNum < 0 printNum 0 {
			printNum = 0;
		} printNum = 0 printNum 0 System.out.println(printNum) System.out.println System.out System System.out printNum String args[] args public class Main{
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	}
} public class Main{
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	}
} Main
import java.util.Scanner;

public class Main{
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		int capacityOfA = scan.nextInt();
		int waterInA = scan.nextInt();
		int waterInB= scan.nextInt();
		int printNum = waterInB - (capacityOfA - waterInA);
		if(printNum < 0){
			printNum = 0;
		}
		System.out.println(printNum);
	}
}