#include <bits/stdc++.h>
#define X first
#define Y second
#define ll long long
#define INF (ll)(1e9 + 7)
#define rep(i, x, n) for (int i = x; i < n; i++)
#define rev(A) reverse((A).begin(), (A).end())
#define sorv(A) sort((A).begin(), (A).end())
#define pb push_back
#define ios ios::sync_with_stdio(false)
#define db(...) ZZ(#__VA_ARGS__, __VA_ARGS__)
#define dbv(v) cout << "Printing "#v << " --> \n"; for(int i=0;i<v.size();i++) cout << v[i] << " "; cout << "\n";
#define dbst(st) cout << "Printing "#st << " --> \n"; for(auto i=st.begin();i!=st.end();i++) cout << *i << " "; cout << "\n";
#define dbmp(mp) cout << "Printing "#mp << " --> \n"; for(auto i=mp.begin();i!=mp.end();i++) cout << #mp"[" << i->first << "]"<< " = " << i->second << "\n";
template <typename Arg1>void ZZ(const char* name, Arg1&& arg1){std::cout << name << " = " << arg1 << std::endl;}
template <typename Arg1, typename... Args>void ZZ(const char* names, Arg1&& arg1, Args&&... args)
{
    const char* comma = strchr(names + 1, ',');
    std::cout.write(names, comma - names) << " = " << arg1;
    ZZ(comma, args...);
}
using namespace std;

ll t, n, q;
ll ans = 1;
ll factorials[1242];
ll C[1300];

ll nCrModpDP(ll n, ll r, ll p)
{
    p = INF;
    memset(C, 0, sizeof(C));
 
    C[0] = 1; // Top row of Pascal Triangle
 
    for (ll i = 1; i <= n; i++)
    {
        // Fill entries of current row using previous
        // row values
        for (ll j = min(i, r); j > 0; j--)
 
            // nCj = (n-1)Cj + (n-1)C(j-1);
            C[j] = (C[j] + C[j-1])%p;
    }
    return C[r];
}

ll nCr(ll N, ll R)
{
	ll p = INF;
    if (R == 0)
      return 1;
    ll ni = N % p, ri = R % p;
    return (nCr(N/p, R/p) * nCrModpDP(ni, ri, p)) % p;
}

ll nPr(ll N, ll R)
{
	return (factorials[R] * nCr(N, R)) % INF;
}

void find_factorials()
{
	factorials[0] = 1;
	for (ll i = 1; i <= n; i++)
	{
		factorials[i] = (factorials[i - 1] * i) % INF;
	}
}

void calc (ll* columns)
{
	for (ll i = 1; columns[i] > 1; i++)
	{
		ans = (ans * factorials[columns[i]]) % INF;
	}
}

void arrange(ll rows, ll current)
{
	if (rows >= current)
	{
		ans = (ans * nPr(rows, current)) % INF;
		return;
	}
	for (ll i = 1; i <= rows; i++)
	{
		ll columns[current + 1];
		ll elements = i;
		columns[1] = i;
		ll j;
		for (j = 2; elements > 0; j++)
		{
			columns[j] = 1;
			elements--;
		}
		ll last_column = j - 1;
		j = last_column;
		calc(columns);
		while(columns[j - 1] != i)
		{
			ll k = 2;
			while (k + 1 <= j)
			{
				columns[k]++;
				columns[j]--;
				k++;
				if (columns[j] == 0)
				{
					j--;
				}
				calc(columns);
			}
		}
	}
}

int main()
{
	ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
	cin >> n;
	find_factorials();
	ll ar[n];
	for (ll i = 0; i < n; i++)
	{
		cin >> ar[i];
	}
	int inv[n + 1] = {0};
	for (ll i = 1; i < n; i++)
	{
		if (ar[i] < ar[i - 1])
		{
			inv[i] = 'y';
		}
	}
	inv[n] = 'e' + 'n' + 'd';
	ll rows = 1;
	for (ll i = 0; i < n; i++)
	{
		if (inv[i + 1] == 'y')
		{
			rows = i + 1;
			break;
		}
		else if (inv[i + 1] == 'e' + 'n' + 'd')
		{
			ans = ((nPr(i + 1, i + 1)) % INF) - i;
			break;
		}
	}
	ll current = 0;
	for (ll i = rows; i < n; i++)
	{
		current++;
		if (inv[i + 1] == 'y')
		{
			while (current >= rows)
			{
				current -= rows;
				ans = (ans * factorials[rows]) % INF;
			}
			if (current > 0)
			{
				rows = current;
				ans = (ans * factorials[rows]) % INF;
			}
		}
		else if (inv[i + 1] == 'e' + 'n' + 'd')
		{
			arrange(rows, current);
			break;
		}
	}
	cout << ans << endl;
	return 0;
}