import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner reader = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
		int A, B, C, mili=0;
		A = reader.nextInt();
		B = reader.nextInt();
		C = reader.nextInt();
		mili = (B+C)-A;
		if(mili>0) {
			System.out.println(mili);
		}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