import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {

	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int max= sc.nextInt();
		int current=sc.nextInt();
		int c=sc.nextInt();
		if(c-(max-current)<0){
			System.out.println(0);
		}else {
		System.out.println(c-(max-current));
		}
	}
} import java.util.Arrays; Arrays java.util import java.util.Comparator; Comparator java.util import java.util.Scanner; Scanner java.util public class Main {

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

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

	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int max= sc.nextInt();
		int current=sc.nextInt();
		int c=sc.nextInt();
		if(c-(max-current)<0){
			System.out.println(0);
		}else {
		System.out.println(c-(max-current));
		}
	}
} Main
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {

	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int max= sc.nextInt();
		int current=sc.nextInt();
		int c=sc.nextInt();
		if(c-(max-current)<0){
			System.out.println(0);
		}else {
		System.out.println(c-(max-current));
		}
	}
}
