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);
       }
     }
   }
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz