import heapq
N,M = map(int,raw_input().split())
C = map(int, raw_input().split())
heapq.heapify(C)
ans = 0
while (M):
    a = heapq.heappop(C)
    a -= 1
    M -=1
    if (a != 0):
        heapq.heappush(C, a)
    else:
        ans += 1
print ans