import java.util.*;

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