import java.util.Scanner;

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

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