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();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  }
} 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();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  }
} 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();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  } main {
    Scanner sc=new Scanner(System.in);
    int a=sc.nextInt();
    int b=sc.nextInt();
    int c=sc.nextInt();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  } 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 int t=a-b; t a-b a b if(c-t<=0){
      System.out.println("0");
    } c-t<=0 c-t c t 0 {
      System.out.println("0");
    } System.out.println("0") System.out.println System.out System System.out "0" if(t<c){
      System.out.println(c-t);
    } t<c t c {
      System.out.println(c-t);
    } System.out.println(c-t) System.out.println System.out System System.out c-t c t 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();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  }
} 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();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  }
} 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();
    int t=a-b;
    if(c-t<=0){
      System.out.println("0");
    }
    if(t<c){
      System.out.println(c-t);
    }
  }
}