import java.util.*;

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 n=c-d;
    if(n<0)
    {
      n=0;
    }
    System.out.print(n);

  }
}
/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