#include <iostream>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <unordered_map>

using namespace std;
typedef long long ll;
const int MAX = 1300;
const ll mod = 1000000007LL;
ll factorial[MAX];
void calcFactorial(int n){
    factorial[0] = 1;
    for(int i = 1;i<=n;++i){
        factorial[i] = (i*factorial[i-1]) % mod;
    }
}

ll pow(ll a, ll p){
    if(p == 0){
        return 1;
    }
    ll res = pow(a, p/2);
    res *= res;
    res %= mod;
    if(p % 2 == 1){
        res *= a;
        res %= mod;
    }
    return res;
}

ll dp[1201][1201];
ll choose[1201][1201];

void generateChoose(int n){
    choose[0][0] = 1;
    for(int i = 1;i<=n;++i){
        for(int j = 0;j<=i;++j){
            choose[i][j] = 0;
            if(j > 0){
                choose[i][j] += choose[i-1][j-1];
                choose[i][j] %= mod;
            }
            if(j <= i-1){
                choose[i][j] += choose[i-1][j];
                choose[i][j] %= mod;
            }
        }
    }
}

inline ll getRes(int maxRow, int pos, bool *br, int n){
    if(pos == n){
        return 1;
    }
    if(maxRow == 1){
        return 1;
    }
    if(dp[maxRow][pos] != -1){
        return dp[maxRow][pos];
    }
    ll res = 0;
    /// apply curr row
    for(int row = 1;row <= maxRow && pos+row <= n && (row == 1 || !br[pos+row-1]);++row){
        res += (((choose[maxRow][row]*factorial[row]) % mod)*getRes(row, pos+row, br, n)) % mod;
        res %= mod;
    }
    return dp[maxRow][pos] = res;
}


int main(){
    ios::sync_with_stdio(false);
    int n;
    cin>>n;
    calcFactorial(n+1);
    generateChoose(n);
    int m[n];
    for(int i = 0;i<n;++i){
        cin>>m[i];
    }
    bool br[n+1];
    for(int i = 0;i<n+1;++i){
        br[i] = false;
    }
    for(int i = 1;i<n;++i){
        if(m[i] < m[i-1]){
            br[i] = true;
        }
    }
    for(int i = 0;i<=1200;++i){
        for(int j = 0;j<=1200;++j){
            dp[i][j] = -1;
        }
    }
    ll res = 0;
    for(int i = 1;i<=n;++i){
        if(br[i-1]){
            break;
        }
        res += getRes(i, i, br, n);
        res %= mod;
    }
    cout<<res;
    return 0;
}