#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define mp make_pair
#define forn(i, n) for (int i = 0; i < (int)(n); ++i)
typedef long long LL;
typedef pair<int, int> PII;

const int MOD = int(1e9) + 7;

int n;
int a[1205], to[1205];
int d[1205][1205];

int main() {
    //freopen("input.txt", "r", stdin);
    scanf("%d", &n);
    forn(i, n) scanf("%d", a + i), --a[i];
    forn(i, n) {
        to[i] = i;
        while (to[i] < n - 1 && a[to[i]] < a[to[i] + 1]) {
            ++to[i];
        }
    }
    memset(d, 0, sizeof d);
    for (int i = 1; i <= to[0] + 1; ++i) {
        d[i][i] = 1;
    }

    for (int i = 1; i < n; ++i) {
        for (int j = 1; j <= n; ++j) if (d[i][j]) {
            int val = d[i][j];
            for (int k = 1; k <= min(j, to[i] - i + 1); ++k) {
                val = (LL)val * (j - k + 1) % MOD;
                d[i + k][k] += val;
                if (d[i + k][k] >= MOD) {
                    d[i + k][k] -= MOD;
                }
            }
        }
    }

    int ans = 0;
    forn(i, n + 1) {
        ans += d[n][i];
        if (ans >= MOD) {
            ans -= MOD;
        }
    }
    cout << ans << endl;
    return 0;
}