import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
			
		int N = sc.nextInt();
		int X = sc.nextInt();
		int[] A = new int[N + 1];
		
		int sum = 0;
		
		for(int i = 1; i <= N; i++) {
			A[i] = sc.nextInt();
			sum = sum + A[i];
		}
		
		System.out.println(Math.max( sum - X, 0));
		
	}
}