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

#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define all(c) c.begin(),c.end()
const int inf = 1000000001;
const ll INF = 2e18;
const ll MOD = 1000000007;
const ll mod = 1000000009;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };

ll mod_pow(ll x, ll p, ll M) {
	ll a = 1;
	while (p) {
		if (p % 2)
			a = a*x%M;
		x = x*x%M;
		p /= 2;
	}
	return a;
}

ll mod_inverse(ll a, ll m) {
	return mod_pow(a, m - 2, m);
}

int main() {
	int n;
	cin >> n;
	string s;
	rep(i, n) {
		char c;
		cin >> c;
		s.push_back(c);
	}
	int m;
	vs first;
	if (s[0] == '0') {
		m = 3;
		first.resize(m);
		first[0] = "000"; first[1] = "100"; first[2] = "111";
	}
	else {
		m = 5;
		first.resize(m);
		first[0] = "001"; first[1] = "010"; first[2] = "011";
		first[3] = "101"; first[4] = "110";
	}
	ll res = 0;
	set<string> st0, st1;
	st0.insert("100");
	st0.insert("000");
	st0.insert("111");
	st1.insert("001");
	st1.insert("010");
	st1.insert("011");
	st1.insert("101");
	st1.insert("110");
	DEBUG(s);
	rep(i, m) {
		string ans(n, '?');
		ans[0] = first[i][1];
		ans[1] = first[i][2];
		ans[n - 1] = first[i][0];
		ll temp = 1;
		for (int j = 1; j < n - 2; j++) {
			if (ans[j - 1] == '0' && ans[j] == '0') {
				ans[j + 1] = s[j];
			}
			else if (ans[j - 1] == '1' && ans[j] == '0') {
				ans[j + 1] = s[j];
			}
			else if (ans[j - 1] == '1' && ans[j] == '1') {
				ans[j + 1] = '0' + (1 - (s[j] - '0'));
			}
			else if (ans[j - 1] == '0' && ans[j] == '1') {
				if (s[j] == '0') {
					temp = 0;
					break;
				}
				else {
					ans[j + 1] = '2';
					temp *= 2;
				}
			}
			else {
				ans[j + 1] = s[j];
			}
		}
		ans.push_back(ans[0]);
		for (int j = n - 2; j <= n - 1; j++) {
			if (temp == 0) {
				continue;
			}
			if (s[j] == '0') {
				string a = ans.substr(j - 1, 3);
				if (st0.count(a)) {
					continue;
				}
				else if (a[0] == '2') {
					if (a.substr(1, 2) != "00") {
						if (a.substr(1, 2) == "11") {
							(temp *= mod_inverse(2, MOD)) %= MOD;
							ans[j] = '1';
						}
						else {
							temp = 0;
						}
					}
				}
				else if (a[1] == '2') {
					if (a[0] == '0' &&  a[2] == '1') {
						temp = 0;
					}
					else {
						a[1] = a[2];
						(temp *= mod_inverse(2, mod)) %= MOD;
					}
				}
				else {
					temp = 0;
				}
			}
			else {
				string a = ans.substr(j - 1, 3);
				if (st1.count(a)) {
					continue;
				}
				else if (a[0] == '2') {
					if (a.substr(1, 2) != "01" && a.substr(1, 2) != "10") {
						if (a.substr(1, 2) == "11") {
							(temp *= mod_inverse(2, MOD)) %= MOD;
							ans[j] = '0';
						}
						else {
							temp = 0;
						}
					}
				}
				else if (a[1] == '2') {
					if (a[0] == '0' &&  a[2] == '0') {
						ans[j + 1] = '1';
						(temp *= mod_inverse(2, MOD)) %= MOD;
					}
					else if (a[0] == '0' &&  a[2] == '1') {
						continue;
					}
					else if (a[0] == '1' &&  a[2] == '0') {
						ans[j + 1] = '1';
						(temp *= mod_inverse(2, MOD)) %= MOD;
					}
					else if (a[0] == '1' &&  a[2] == '1') {
						ans[j + 1] = '0';
						(temp *= mod_inverse(2, MOD)) %= MOD;
					}
				}
				else {
					temp = 0;
				}
			}
		}
		DEBUG(temp);
		(res += temp) % MOD;
	}
	cout << res << endl;

}