#include using namespace std; #define int long long #define ii pair #define app push_back #define all(a) a.begin(), a.end() #define bp __builtin_popcountll #define ll long long #define mp make_pair #define x first #define y second #define Time (double)clock()/CLOCKS_PER_SEC #define debug(x) std::cout << #x << ": " << x << '\n'; #define FOR(i, n) for (int i = 0; i < n; ++i) #define pb push_back #define trav(a, x) for (auto& a : x) using vi = vector; template std::ostream& operator <<(std::ostream& output, const pair & data) { output << "(" << data.x << "," << data.y << ")"; return output; } template std::ostream& operator <<(std::ostream& output, const std::vector& data) { for (const T& x : data) output << x << " "; return output; } ll div_up(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up ll div_down(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down #define tcT template using V = vector; tcT> void re(V& x) { trav(a, x) cin >> a; } tcT> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; } // set a = min(a,b) tcT> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; } const int INF = 1e16; int mul(int a, int b) { if (a == 0 || b == 0) return 0; if (b > INF/a) return INF; else return a * b; } //need define int long long namespace Stuff { const int MOD = 1e9+7; int mod(int n) { n %= MOD; if (n < 0) return n + MOD; else return n; } int fp(int a, int p) { int ans = 1, c = a; for (int i = 0; (1ll << i) <= p; ++i) { if ((p >> i) & 1) ans = mod(ans * c); c = mod(c * c); } return ans; } int dv(int a, int b) { return mod(a * fp(b, MOD - 2)); } }; struct M { ll x; M (int x_) { x = Stuff::mod(x_); } M () { x = 0; } M operator + (M y) { int ans = x + y.x; if (ans >= Stuff::MOD) ans -= Stuff::MOD; return M(ans); } M operator - (M y) { int ans = x - y.x; if (ans < 0) ans += Stuff::MOD; return M(ans); } M operator * (M y) { return M(x * y.x % Stuff::MOD); } M operator / (M y) { return M(x * Stuff::fp(y.x, Stuff::MOD - 2) % Stuff::MOD); } M operator + (int y) { return (*this) + M(y); } M operator - (int y) { return (*this) - M(y); } M operator * (int y) { return (*this) * M(y); } M operator / (int y) { return (*this) / M(y); } M operator ^ (int p) { return M(Stuff::fp(x, p)); } void operator += (M y) { *this = *this + y; } void operator -= (M y) { *this = *this - y; } void operator *= (M y) { *this = *this * y; } void operator /= (M y) { *this = *this / y; } void operator += (int y) { *this = *this + y; } void operator -= (int y) { *this = *this - y; } void operator *= (int y) { *this = *this * y; } void operator /= (int y) { *this = *this / y; } void operator ^= (int p) { *this = *this ^ p; } bool operator == (M y) { return x == y.x; } }; std::ostream& operator << (std::ostream& o, const M& a) { cout << a.x; return o; } const int N = 101; int dp[N]; signed main() { #ifdef HOME freopen("input.txt", "r", stdin); #else #define endl '\n' ios_base::sync_with_stdio(0); cin.tie(0); #endif int n; cin >> n; vi a(n); re(a); int f = 1; trav (x, a) f = mul(f, x); if (f == INF) { M ans = 1; trav (x, a) ans *= x; int ptr = 0; while (a[ptr] == 1) { ans += 1; ptr++; } ptr = n - 1; while (a[ptr] == 1) { ans += 1; ptr--; } cout << ans << endl; exit(0); } vi p; FOR (i, n) if (a[i] > 1) p.app(i); if (p.empty()) { cout << n << endl; exit(0); } int sz = p.size(); for (int i = 0; i < sz; ++i) { int f = 1; for (int l = i; l >= 0; --l) { f *= a[p[l]]; int nn = f; if (l > 0) { nn += dp[l - 1]; int ones = p[l] - p[l - 1] - 1; nn += ones; } ckmax(dp[i], nn); } assert(dp[i] < INF); } M ans = dp[sz - 1]; int ptr = 0; while (a[ptr] == 1) { ans += 1; ptr++; } ptr = n - 1; while (a[ptr] == 1) { ans += 1; ptr--; } cout << ans << endl; }