import java.util.* ;
class Main {
  public static void main(String[] args) {
    
    Scanner scan = new Scanner(System.in);

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

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

	int a = scan.nextInt();
    int b = scan.nextInt();
    int c = scan.nextInt();
    
    int x = a-b;
    if(c<=x){
      System.out.println(0);
    }else{
      int y = Math.abs(c-x);
      System.out.println(y);
    }
    
    
    
  } main {
    
    Scanner scan = new Scanner(System.in);

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

	int a = scan.nextInt();
    int b = scan.nextInt();
    int c = scan.nextInt();
    
    int x = a-b;
    if(c<=x){
      System.out.println(0);
    }else{
      int y = Math.abs(c-x);
      System.out.println(y);
    }
    
    
    
  }
}

