import java.util.Scanner;

public class Main{
  public static void main(String[] args){

    Scanner sc = new Scanner(System.in);

    int A = sc.nextInt();
    int B = sc.nextInt();
    int C = sc.nextInt();

    int D = A - B;

    int E = C - D;

    if(E < 0){
      E = 0;
    }
    System.out.println(E);
    
  }
}
/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