import java.util.Scanner;

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 ans=c+b-a;
    if(ans<0){
      System.out.println(0);
    }else{
      System.out.println(c+b-a);
    }
  }
}
/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