import static java.lang.System.*;
import java.util.*;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	}
} import static java.lang.System.*; import static java.lang.System.*; import static java.lang.System.*; import java.util.*; util.* java public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	} main {
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n[] = new int[4]; n new int[4] 4 for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		} int i = 0; int i = 0; i 0 i < 3 i 3 i++ i++ i {
			n[i] = sc.nextInt();
		} {
			n[i] = sc.nextInt();
		} n[i] = sc.nextInt() n[i] n i sc.nextInt() sc.nextInt sc n[3] = n[2] - (n[0] - n[1]) n[3] n 3 n[2] - (n[0] - n[1]) n[2] n 2 (n[0] - n[1]) n[0] n 0 n[1] n 1 out.println((0 < n[3])? n[3]:0) out.println out (0 < n[3])? n[3]:0 (0 < n[3]) 0 n[3] n 3 n[3] n 3 0 String[] args args public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	}
} public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	}
} Main
import static java.lang.System.*;
import java.util.*;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n[] = new int[4];
		for(int i = 0;i < 3; i++){
			n[i] = sc.nextInt();
		}
		n[3] = n[2] - (n[0] - n[1]);
		out.println((0 < n[3])? n[3]:0);
	}
}
