import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	} main {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) StringBuilder sb = new StringBuilder(); sb new StringBuilder() 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) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		} a <= b + c a b + c b c {
			sb.append(b+c - a);
		} sb.append(b+c - a) sb.append sb b+c - a b+c b c a {
			sb.append(0);
		} sb.append(0) sb.append sb 0 System.out.println(sb) System.out.println System.out System System.out sb String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if (a <= b + c) {
			sb.append(b+c - a);
		} else {
			sb.append(0);
		}
		System.out.println(sb);
	}
}