import java.util.*;

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();

    System.out.println(transferTask(a, b, c));
  }

  private static int transferTask(int a, int b, int c) {
    int result = c - (a - b);
    if(result < 0) {
      return 0;
    }
    return 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