import sys
from itertools import accumulate
input = sys.stdin.readline
sys.setrecursionlimit(10**7)

N = int(input())
P = list(map(int,input().split()))

pos = [0]*(N+1)
for i in range(N):
    pos[P[i]] = i+1

S_pos = list(accumulate(pos))
ans = 0
for i in range(1,N+1):
    ans = max(ans,S_pos[i-1]-pos[i])

print(ans)