import java.util.*;

public class Main {

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

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

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

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt(), b = sc.nextInt(), c = sc.nextInt();
		sc.close();
		int ans = c - (a - b);
      	if(c < (a - b))ans = 0;
		System.out.println(ans);
	}
} Main
import java.util.*;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt(), b = sc.nextInt(), c = sc.nextInt();
		sc.close();
		int ans = c - (a - b);
      	if(c < (a - b))ans = 0;
		System.out.println(ans);
	}
}
