# 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)
    c[c.index(minimum)] -= 1

for i in range(n):
    if c[i] == 0:
        zero_box += 1

print(zero_box)