区间dp 3146 3205

 

 

dp=[[0 for i in range(250)] for i in range(250)]
ans=0
n=int(input())
for i in range(1,n+1):
    dp[i][i]=int(input())
    ans=max(ans,dp[i][i])
for j in range(1,n):
    for i in range(1,n+1):
        if (i+j>n):continue
        for k in range(j):
            if (dp[i][i+k]>0 and    dp[i][i+k]==dp[i+k+1][i+j]):
                dp[i][i+j]=max(dp[i][j+i],dp[i][i+k]+1)
                ans=max(ans,dp[i][i+j])
print(ans)

 

 

mod=19650827
n=int (input())
num=[0]+list(map(int ,input().split()))
dp=[[0 for i in range(n+10)] for i in range(n+10)]
for i in range(1,n+1):
    dp[i][i]=1
for j in range(1,n):
    for i in range(1,n+1):
        if (i+j>n): continue

        if (num[i]<num[j+i] and j!=1):
            dp[j+i][i]+=dp[i+1][i+j]
            dp[j+i][i]%=mod
            dp[i][j+i]+=dp[i+j-1][i]
            dp[i][j+i]%=mod
        if (num[i]<num[i+1]):
            dp[j+i][i]+=dp[j+i][i+1]
            dp[j + i][i] %= mod
        if (num[j+i]>num[j+i-1]):
            dp[i][j+i]+=dp[i][j+i-1]
            dp[i][j + i] %= mod

print((dp[1][n]+dp[n][1])%mod)