#include <bits/stdc++.h>
using namespace std;

#define MOD 1000000007

int A[1203], lim[1203];
long long dp[1203][1203], C[1203][1203], fact[1203];

long long mod(long long N)
{
    if(N>=MOD)
        N%= MOD;
    
    return N;
}

int main()
{
    int N;
    scanf("%d", &N);
    
    fact[0] = 1;
    
    for(int i=1; i<=1200; i++)
        fact[i] = fact[i-1]*i%MOD;
    
    for(int i=0; i<=1200; i++)
        C[i][0] = 1;
    
    for(int i=1; i<=1200; i++)
        for(int j=1; j<=i; j++)
            C[i][j] = (C[i-1][j-1] + C[i-1][j])%MOD;
    
    for(int i=1; i<=N; i++)
        scanf("%d", &A[i]);
    
    for(int i=1; i<=N; i++)
    {
        if(i>1 && A[i]>A[i-1])
            lim[i] = lim[i-1];
        else
            lim[i] = i;
    }
    
    // dp[i][j] = number of ways to divide such that the last partition
    //          ended at i, and its size was j
    
    // dp[i][j] = (dp[i-j][j]*nCr(j, j) + dp[i-j][j+1]*nCr(j+1, j) + dp[i-j][j+2]*nCr(j+2, j) + ...) * fact(j);
    
    for(int i=1; i<=N; i++)
    {
        for(int j=1; j<=N; j++)
        {
            if(i-j>=0 && i-j+1>=lim[i])
            {
                if(j==i)
                {
                    dp[i][j] = 1;
                    continue;
                }
                
                for(int k=j; k<=i; k++)
                    dp[i][j] += mod(dp[i-j][k]*C[k][j]);
                
                dp[i][j] = mod(mod(dp[i][j])*fact[j]);
            }
        }
    }
    
    long long ans = 0;
    
    for(int i=1; i<=N; i++)
        ans += dp[N][i];
    
    printf("%lld\n", mod(ans));
    
    return 0;
}