# No.156 キャンディー・ボックス n, m = [int(i) for i in input().split()] c = [int(i) for i in input().split()] zero_box = 0 for i in range(m): tmp = [c[j] for j in range(n) if c[j] != 0] minimum = min(tmp) for j in range(n): if c[j] == minimum: c[j] -= 1 break for i in range(n): if c[i] == 0: zero_box += 1 print(zero_box)