import sys

int1 = lambda x: int(x) - 1

# input = lambda: sys.stdin.buffer.readline()
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
i1 = lambda: int1(input())
mi = lambda: map(int, input().split())
mi1 = lambda: map(int1, input().split())
li = lambda: list(mi())
li1 = lambda: list(mi1())
lli = lambda n: [li() for _ in range(n)]

INF = float("inf")
mod = int(1e9 + 7)
# mod = 998244353

n, m = mi()
a = li()
ok = 0
ng = mod
while ng - ok > 1:
    mid = ok + ng >> 1
    b = a[:]
    f = True
    for i in range(n):
        if b[i] < m * mid:
            f = False
        elif i + 1 < n:
            b[i + 1] += b[i] - m * mid
    if f:
        ok = mid
    else:
        ng = mid
print(ok)