import 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    }
}
       import java.util.*; util.* java 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    }
} 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    } 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    } 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(C-(A-B));
      }else{
        System.out.println(0);
      } A-B<=C A-B A B C {
        System.out.println(C-(A-B));
      } System.out.println(C-(A-B)) System.out.println System.out System System.out C-(A-B) C (A-B) A B {
        System.out.println(0);
      } System.out.println(0) System.out.println System.out System System.out 0 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    }
} 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    }
} Main
import 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(C-(A-B));
      }else{
        System.out.println(0);
      }
    }
}
      