from collections import defaultdict

N, S = map(int, input().split())
A = list(map(int, input().split()))

A.sort()

l = 0
r = max(A)

while r - l > 1:
    m = (l + r) // 2

    ok = True
    s = S - 1
    rem = 0
    for a in A:
        if a <= m:
            break
        if rem == 0:
            s -= a
            if s < 0:
                ok = False
                continue
            rem = m - 1
        else:
            rem -= 1
    if ok:
        r = m
    else:
        l = m

print(r)