n,m=map(int,input().split())
a=list(map(int,input().split()))
from itertools import accumulate
s=list(accumulate(a))
def check(x):
    for i in range(n):
        if s[i]<(i+1)*m*x:
            return False
    return True
l=0
r=10**15
while r-l>1:
    x=(r+l)//2
    if check(x):
        l=x
    else:
        r=x
print(l)