import java.util.Scanner;

public class Main {


	public static void main(String[] args) {
		(new Main()).execute();
	}
	public void execute() {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	}

	public int getAnswer(int A, int B, int C) {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	}

} import java.util.Scanner; Scanner java.util public class Main {


	public static void main(String[] args) {
		(new Main()).execute();
	}
	public void execute() {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	}

	public int getAnswer(int A, int B, int C) {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	}

} Main public static void main(String[] args) {
		(new Main()).execute();
	} main {
		(new Main()).execute();
	} (new Main()).execute() (new Main()).execute (new Main()) String[] args args public void execute() {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	} execute {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc 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 ans = getAnswer(A,B,C) ; ans getAnswer(A,B,C) getAnswer A B C System.out.println(ans) System.out.println System.out System System.out ans public int getAnswer(int A, int B, int C) {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	} getAnswer {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	} int ans = 0 ; ans 0 int amari = A - B ; amari A - B A B if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		} amari < C amari C {
			ans = C - amari ;
		} ans = C - amari ans C - amari C amari {
			ans = 0 ;
		} ans = 0 ans 0 return ans ; ans int A A int B B int C C public class Main {


	public static void main(String[] args) {
		(new Main()).execute();
	}
	public void execute() {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	}

	public int getAnswer(int A, int B, int C) {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	}

} public class Main {


	public static void main(String[] args) {
		(new Main()).execute();
	}
	public void execute() {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	}

	public int getAnswer(int A, int B, int C) {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	}

} Main
import java.util.Scanner;

public class Main {


	public static void main(String[] args) {
		(new Main()).execute();
	}
	public void execute() {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int ans = getAnswer(A,B,C) ;
		System.out.println(ans);
	}

	public int getAnswer(int A, int B, int C) {
		int ans = 0 ;
		int amari = A - B ;

		if(amari < C) {
			ans = C - amari ;
		}else {
			ans = 0 ;
		}

		return ans ;
	}

}
