#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9+7;

long long inv(long long x){
    x%=MOD;
    assert(x);
    long long ret=1ll;
    for(long long i=1;i<=MOD;i<<=1){
        if((MOD-2)&i){
            ret = ret*x%MOD;
        }
        x = x*x%MOD;
    }
    return ret;
}

vector<long long> fcache;
vector<long long> ifcache;
long long fact(int i){
    return fcache[i];
}
long long factinv(int i){
    return ifcache[i];
}

void buildf(int top){
    top+=3;
    fcache.resize(top);
    ifcache.resize(top);
    for(int i=fcache[0]=1;i<top;++i) fcache[i] = i*fcache[i-1]%MOD;
    ifcache.back()=inv(fcache.back());
    for(int i=top-1;i>0;--i)ifcache[i-1]=i*ifcache[i]%MOD;
    assert(ifcache[0]==1);
}
void gen(int N){
    freopen("out.txt", "w", stdout);
    cout << N << "\n";
    for(int i=1;i<=N;++i){
        cout << i << " ";
    }
    cout << endl;
    exit(0);
}

//O(N^3/6), could be O(N^2 log N) by using FFT.
signed main(){
    #ifdef LOCAL_RUN
    freopen("in.txt", "r", stdin);
    #endif // LOCAL_RUN
    int N;cin >> N;
    if(N<0) gen(-N);
    buildf(N);
    vector<int> a(N);
    copy_n(istream_iterator<int>(cin), N, a.begin());
    vector<vector<long long> > DP(N+1, vector<long long>(N+1, 0));
    fill(DP[0].begin(), DP[0].end(), 1ll);
    for(int i=1;i<=N;++i){
        for(int j=i;j>=0;--j){
            if(j<i-1&& a[j]>a[j+1]) break;
            DP[i][i-j]=fact(i-j)*DP[j][i-j]%MOD;
        }
        for(int j=0;j<=i;++j){
            //cerr << i << "/" << j << " : " << DP[i][j] << "\n";
            for(int k=j+1;k<=i;++k){/// FFT ??
                DP[i][j]+=DP[i][k]*factinv(k-j)%MOD;
            }
            DP[i][j]%=MOD;
        }
        //for(int j=N;j>=0;--j) cerr << i << "/" << j << " : " << DP[i][j] << "\n";


    }
    cout << DP[N][0] << "\n";
}