import java.util.Scanner;

public class Main {

	private void solve() {
		Scanner in = new Scanner(System.in);
		int A = in.nextInt();
		int B = in.nextInt();
		int C = in.nextInt();
		
		int ans = C - (A - B) ;
		System.out.println((ans<0)?0:ans);
	}

	public static void main(String[] args) {
		new Main().solve();
	}
}
/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