import java.util.Scanner;

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

	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A=sc.nextInt();
		int B=sc.nextInt();
		int C=sc.nextInt();
		if(A-B>C) {
			System.out.println(0);
			return;
		}
		System.out.print(C-A+B);
	

	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int A=sc.nextInt();
		int B=sc.nextInt();
		int C=sc.nextInt();
		if(A-B>C) {
			System.out.println(0);
			return;
		}
		System.out.print(C-A+B);
	

	} main {
		Scanner sc = new Scanner(System.in);
		int A=sc.nextInt();
		int B=sc.nextInt();
		int C=sc.nextInt();
		if(A-B>C) {
			System.out.println(0);
			return;
		}
		System.out.print(C-A+B);
	

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

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

	}
} Main
import java.util.Scanner;

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

	}
}
