import java.util.Scanner;

public 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 rest;
    if(B+C < A) {rest =0;}
    else rest = B+C-A;

	
	
	System.out.println(rest);

		
	}

}

/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