n, m = map(int, input().split())
C = list(map(int, input().split()))
import heapq
heapq.heapify(C)
ans = 0
for i in range(m):
    c = heapq.heappop(C)
    if c == 1:
        ans += 1
    else:
        heapq.heappush(C, c-1)
print(ans)