n, m = map(int, input().split())
a = list(map(int, input().split()))
l, r = -1, 10 ** 9 + 1
while r - l > 1:
    mid = (l + r) // 2
    amari = 0
    for i in a:
        if i >= mid * m:
            amari += i - mid * m
        else:
            if amari < mid * m - i:
                r = mid
                break
            amari -= mid * m - i
    else: l = mid
print(l)