import java.util.Scanner;

class Main{
  public static void main(String[] arg){
    Scanner scan=new Scanner(System.in);
    int a=scan.nextInt();
    int b=scan.nextInt();
    int c=scan.nextInt();
    if(a-b<=c){
      System.out.println(c-a+b);
    }else{
      System.out.println(0);
    }
  }
} import java.util.Scanner; Scanner java.util class Main{
  public static void main(String[] arg){
    Scanner scan=new Scanner(System.in);
    int a=scan.nextInt();
    int b=scan.nextInt();
    int c=scan.nextInt();
    if(a-b<=c){
      System.out.println(c-a+b);
    }else{
      System.out.println(0);
    }
  }
} Main public static void main(String[] arg){
    Scanner scan=new Scanner(System.in);
    int a=scan.nextInt();
    int b=scan.nextInt();
    int c=scan.nextInt();
    if(a-b<=c){
      System.out.println(c-a+b);
    }else{
      System.out.println(0);
    }
  } main {
    Scanner scan=new Scanner(System.in);
    int a=scan.nextInt();
    int b=scan.nextInt();
    int c=scan.nextInt();
    if(a-b<=c){
      System.out.println(c-a+b);
    }else{
      System.out.println(0);
    }
  } Scanner scan=new Scanner(System.in); scan new Scanner(System.in) int a=scan.nextInt(); a scan.nextInt() scan.nextInt scan int b=scan.nextInt(); b scan.nextInt() scan.nextInt scan int c=scan.nextInt(); c scan.nextInt() scan.nextInt scan 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 c a b {
      System.out.println(0);
    } System.out.println(0) System.out.println System.out System System.out 0 String[] arg arg
import java.util.Scanner;

class Main{
  public static void main(String[] arg){
    Scanner scan=new Scanner(System.in);
    int a=scan.nextInt();
    int b=scan.nextInt();
    int c=scan.nextInt();
    if(a-b<=c){
      System.out.println(c-a+b);
    }else{
      System.out.println(0);
    }
  }
}