import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner stdIn=new Scanner(System.in);
		int a=stdIn.nextInt();
		int b=stdIn.nextInt();
		int c=stdIn.nextInt();
		int x=b+c;
		if(a<x)
			System.out.println(x-a);
		else
			System.out.println("0");

	}

}

/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