from itertools import accumulate
N, M = map(int, input().split())
A = list(map(int, input().split()))
R = list(accumulate(A))

def solve(m): # m 個作れるとする
    for i in range(N):
        if R[i] < (i + 1)*m*M:
            break
    else:
        return True
    return False

ok = 0
ng = 10**9 + 1
while abs(ok - ng) != 1:
    mid = (ok + ng)//2
    if solve(mid):
        ok = mid
    else:
        ng = mid
print(ok)