import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  }
} Main public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  } main {
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int A=sc.nextInt() A sc.nextInt() sc.nextInt sc B=sc.nextInt() B sc.nextInt() sc.nextInt sc C=sc.nextInt() C sc.nextInt() sc.nextInt sc D=A-B; D A-B A B if(C<=D) System.out.println(0);
    else System.out.println(C-D); C<=D C D System.out.println(0) System.out.println System.out System System.out 0 System.out.println(C-D) System.out.println System.out System System.out C-D C D String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  }
} Main
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int A=sc.nextInt(), B=sc.nextInt(), C=sc.nextInt(), D=A-B;
    if(C<=D) System.out.println(0);
    else System.out.println(C-D);
  }
}