There are n psychos standing in a line. Each psycho is assigned a unique integer from 1 to n. At each step every psycho who has an id greater than the psycho to his right (if exists) kills his right neighbor in the line. Note that a psycho might kill and get killed at the same step. 

You're given the initial arrangement of the psychos in the line. Calculate how many steps are needed to the moment of time such, that nobody kills his neighbor after that moment. Look notes to understand the statement more precise.


-----Input-----

The first line of input contains integer n denoting the number of psychos, (1 ≤ n ≤ 10^5). In the second line there will be a list of n space separated distinct integers each in range 1 to n, inclusive — ids of the psychos in the line from left to right.


-----Output-----

Print the number of steps, so that the line remains the same afterward.


-----Examples-----
Input
10
10 9 7 8 6 5 3 4 2 1

Output
2

Input
6
1 2 3 4 5 6

Output
0



-----Note-----

In the first sample line of the psychos transforms as follows: [10 9 7 8 6 5 3 4 2 1]  →  [10 8 4]  →  [10]. So, there are two steps.

Difficulty: competition

Starter code:

Solutions:
n = int(input())
ans = 0
stk = []
for v in map(int, input().split()):
    last = 0
    while len(stk) and stk[-1][0] < v and stk[-1][1]:
        last = max(last, stk[-1][1])
        del stk[-1]

    if not len(stk) or stk[-1][0] < v:
        stk.append((v, 0))
    else:
        stk.append((v, last + 1)); ans = max(ans, last + 1)
print(ans)


n, t = int(input()), list(map(int, input().split()))
p, s, r = [0] * n, [0] * n, t[0]
for i in range(n - 1):
    j = i + 1
    x = t[j]
    if x > r: r = x
    else:
        while t[i] < x: s[j], i = max(s[j], s[i]), p[i]
        p[j] = i
        s[j] += 1
print(max(s))

n = int(input())
ans = 0
stk = []
for v in map(int, input().split()):
    last = 0
    while len(stk) and stk[-1][0] < v and stk[-1][1]:
        last = max(last, stk[-1][1])
        del stk[-1]

    if not len(stk) or stk[-1][0] < v:
        stk.append((v, 0))
    else:
        stk.append((v, last + 1));
        ans = max(ans, last + 1)
print(ans)

n, t = int(input()), list(map(int, input().split()))

p, s, r = [0] * n, [0] * n, t[0]

for i in range(n - 1):

    j = i + 1

    x = t[j]

    if x > r: r = x

    else:

        while t[i] < x: s[j], i = max(s[j], s[i]), p[i]

        p[j] = i

        s[j] += 1

print(max(s))



# Made By Mostafa_Khaled


n = int(input())
A = [int(i) for i in input().split()]
ans = 0

st = [0]

tdeath = [-1 for i in range(n)]

for i in range(1, n):
    tdeath[i] = 0
    while len(st) > 0 and A[st[-1]] < A[i]:
        tdeath[i] = max(tdeath[i], tdeath[st[-1]]+1)
        st.pop()
    if len(st)==0:
        tdeath[i] = -1
    st.append(i)
    ans = max(ans, tdeath[i]+1)
    
print(ans)


n = int(input())
A = list(map(int,input().strip().split()))[::-1]
p = 0
p_max = 0
X = []
for i in A:
    # print(X)
    while(len(X)>0 and X[-1][0]<i):
        p = max((p+1,X[-1][1]))
        X.pop()
    X.append((i,p))
    if p>p_max:
        p_max = p
    p=0
print(p_max)


N=int(input())
psychos=list(map(int, input().split(" ")))
time_of_death=[0 for i in range(N)]

stack=[(psychos[0], 0)]
for index, p in enumerate(psychos):
    if index==0:
        continue
    if p<stack[-1][0]:
        stack.append((p, 1))
        time_of_death[index]=1

    elif p>stack[-1][0]:
        max_time=-1
        while stack!=[] and p>stack[-1][0]:
            max_time=max(max_time, stack[-1][1])
            del stack[-1]
        if stack==[]:
            # will never die, no bigger psychos to left
            stack.append((p, 0)) 
            time_of_death[index]=0 
        else:
            # will die, bigger psycho to left
            stack.append((p, max_time+1))
            time_of_death[index]=max_time+1

print(max(time_of_death))
    

'''
7
15 9 5 10 7 11 14
'''

def main():

    from bisect import bisect_left as bl, bisect_right as br, insort
    import sys,math
    #from heapq import heapify, heappush, heappop
    from collections import defaultdict as dd, deque
    def data(): return sys.stdin.readline().strip()
    def mdata(): return list(map(int, data().split()))
    out = sys.stdout.write
    # sys.setrecursionlimit(100000)
    INF = float("INF")
    mod = int(1e9)+7

    n=int(data())
    l=mdata()
    cnt=0
    m=0
    max1=0
    X=[]
    for i in l[::-1]:
        while len(X) and X[-1][0]<i:
            m=max(m+1,X[-1][1])
            X.pop()
        X.append([i, m])
        if m>max1:
            max1=m
        m=0
    print(max1)


def __starting_point():
    main()

__starting_point()

from math import sqrt,ceil,gcd
from collections import defaultdict



def modInverse(b,m):
    g = gcd(b, m)
    if (g != 1):
        # print("Inverse doesn't exist")
        return -1
    else:
        # If b and m are relatively prime,
        # then modulo inverse is b^(m-2) mode m
        return pow(b, m - 2, m)

def sol(n,m,rep):

    r = 1
    for i in range(2,n+1):
        j = i
        while j%2 == 0 and rep>0:

            j//=2
            rep-=1

        r*=j
        r%=m

    return r





def solve():

   n = int(input())
   l = list(map(int,input().split()))
   st = []
   ans = 0
   hash = defaultdict(lambda : -1)
   for i in range(n):
       hash[i] = 0


       while st!=[] and l[st[-1]]<l[i]:
               z = st.pop()
               hash[i] = max(hash[i],hash[z]+1)


       if st == []:
           hash[i] = -1
       st.append(i)
       ans = max(ans,hash[i]+1)
   print(ans)


















# t = int(input())
# for _ in range(t):
solve()