#ifndef LOCAL #pragma GCC optimize("Ofast") #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using i64 = int_fast64_t; using pii = pair; using pli = pair; using pll = pair; template using heap = priority_queue; template using minheap = priority_queue, greater>; template constexpr T inf = numeric_limits::max() / (T)2 - (T)123456; constexpr int dx[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0}; constexpr int dy[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0}; constexpr long double Pi = 3.1415926535897932384626433832; constexpr long double Golden = 1.61803398874989484820; #define iostream_untie true #define stdout_precision 10 #define stderr_precision 10 #define itrep(i,v) for(auto i = begin(v); i != end(v); ++i) #define ritrep(i,v) for(auto i = rbegin(v); i != rend(v); ++i) #define rep(i,n) for(int_fast64_t i = 0; i < (int_fast64_t)(n); ++i) #define rrep(i,n) for(int_fast64_t i = (int_fast64_t)(n) - 1; i >= 0; --i) #define all(v) begin(v), end(v) #define rall(v) rbegin(v), rend(v) #define fir first #define sec second #define u_map unordered_map #define u_set unordered_set #define l_bnd lower_bound #define u_bnd upper_bound #define emp emplace #define emf emplace_front #define emb emplace_back #define pof pop_front #define pob pop_back #define mkp make_pair #define mkt make_tuple #define popcnt __builtin_popcount namespace setup { struct setupper { setupper() { if(iostream_untie) { ios::sync_with_stdio(false); std::cin.tie(nullptr); std::cout.tie(nullptr); std::cerr.tie(nullptr); } std::cout << std::fixed << std::setprecision(stdout_precision); std::cerr << std::fixed << std::setprecision(stderr_precision); #ifdef LOCAL if(!freopen("stderr.txt","wt",stderr)) { freopen("CON","wt",stderr); std::cerr << "Failed to open the stderr file\n"; } if(!freopen("stdout.txt","wt",stdout)) { freopen("CON","wt",stdout); std::cerr << "Failed to open the stdout file\n"; } if(!freopen("stdin.txt","rt",stdin)) { freopen("CON","rt",stdin); std::cerr << "Failed to open the stdin file.\n"; } // auto print_atexit = []() { // std::cerr << "Exec time : " << clock() / (double)CLOCKS_PER_SEC * 1000.0 << "ms\n"; // std::cerr << "------------\n"; // }; // atexit((void(*)())print_atexit); #endif } } __setupper; } namespace std { template void rsort(RAitr __first, RAitr __last) { sort(__first, __last, greater<>()); } template void hash_combine(size_t &seed, T const &key) { seed ^= hash()(key) + 0x9e3779b9 + (seed << 6) + (seed >> 2); } template struct hash> { size_t operator()(pair const &pr) const { size_t seed = 0; hash_combine(seed,pr.first); hash_combine(seed,pr.second); return seed; } }; template ::value - 1> struct hashval_calc { static void apply(size_t& seed, tuple_t const& t) { hashval_calc::apply(seed, t); hash_combine(seed,get(t)); } }; template struct hashval_calc { static void apply(size_t& seed, tuple_t const& t) { hash_combine(seed,get<0>(t)); } }; template struct hash> { size_t operator()(tuple const& t) const { size_t seed = 0; hashval_calc>::apply(seed,t); return seed; } }; } template istream &operator>> (istream &s, pair &p) { return s >> p.first >> p.second; } template ostream &operator<< (ostream &s, const pair p) { return s << p.first << " " << p.second; } template istream &operator>> (istream &s, vector &v) { for(T &e : v) { s >> e; } return s; } template ostream &operator<< (ostream &s, const vector &v) { for(size_t i = 0; i < v.size(); ++i) { s << (i ? " " : "") << v[i]; } return s; } template struct tupleos { static ostream &apply(ostream &s, const tuple_t &t) { tupleos::apply(s,t); return s << " " << get(t); } }; template struct tupleos { static ostream &apply(ostream &s, const tuple_t &t) { return s << get<0>(t); } }; template ostream &operator<< (ostream &s, const tuple &t) { return tupleos, tuple_size>::value - 1>::apply(s,t); } template <> ostream &operator<< (ostream &s, const tuple<> &t) { return s; } #define dump(...) cerr << " [ " << __LINE__ << " : " << __FUNCTION__ << " ] " << #__VA_ARGS__ << " : ";\ dump_func(__VA_ARGS__) template void dump_func(T x) { cerr << x << '\n'; } template void dump_func(T x, Rest ... rest) { cerr << x << ","; dump_func(rest...); } template void write(T x) { cout << x << '\n'; } template void write(T x, Rest ... rest) { cout << x << ' '; write(rest...); } void writeln() {} template void writeln(T x, Rest ... rest) { cout << x << '\n'; writeln(rest...); } #define esc(...) writeln(__VA_ARGS__), exit(0) template void read(P __first, P __second) { for(P i = __first; i != __second; ++i) cin >> *i; } namespace updater { template static void add(T &x, const T &y) { x += y; } template static void ext_add(T &x, const T &y, size_t w) { x += y * w; } template static void mul(T &x, const T &y) { x *= y; } template static void ext_mul(T &x, const T &y, size_t w) { x *= (T)pow(y,w); } template static bool chmax(T &x, const T &y) { return x < y ? x = y, true : false; } template static bool chmin(T &x, const T &y) { return x > y ? x = y, true : false; } }; using updater::add; using updater::chmax; using updater::chmin; template constexpr T minf(const T &x, const T &y) { return min(x,y); } template constexpr T maxf(const T &x, const T &y) { return max(x,y); } constexpr bool bit(i64 n, int e) { return (n >> e) & 1; } constexpr int_fast64_t mask(int_fast64_t n, int e) { return n & ((1 << e) - 1); } constexpr int ilog(int_fast64_t x, int_fast64_t b = 2) { return x ? 1 + ilog(x / b, b) : -1; } int_fast64_t binry(int_fast64_t ok, int_fast64_t ng, const function &fn) { while (abs(ok - ng) > 1) { int_fast64_t mid = (ok + ng) / 2; (fn(mid) ? ok : ng) = mid; } return ok; } template void init(A (&array)[N], const T &val) { fill((T*)array,(T*)(array + N),val); } template vector cmprs(const vector &v) { vector tmp = v; vector ret; sort(begin(tmp),end(tmp)); tmp.erase(unique(begin(tmp),end(tmp)), end(tmp)); for(T i : v) ret.emplace_back(lower_bound(begin(tmp),end(tmp),i) - begin(tmp)); return ret; } template vector cmprs(const T *__first, const T *__last) { return cmprs(vector(__first, __last)); } void for_subset(int_fast64_t s, const function &fn) { int_fast64_t tmp = s; do { fn(tmp); } while((--tmp &= s) != s); } /* The main code follows. */ template struct modint { int x; constexpr modint() : x(0) {} constexpr modint(int_fast64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} constexpr modint &operator+=(const modint &p) { if((x += p.x) >= mod) x -= mod; return *this; } constexpr modint &operator++() { return ++x,*this; } constexpr modint operator++(int) { modint t = *this; return ++x,t; } constexpr modint &operator-=(const modint &p) { if((x += mod - p.x) >= mod) x -= mod; return *this; } constexpr modint &operator--() { return --x, *this; } constexpr modint operator--(int) { modint t = *this; return --x,t; } constexpr modint &operator*=(const modint &p) { x = (int) (1LL * x * p.x % mod); return *this; } constexpr modint &operator/=(const modint &p) { *this *= inverse(p); return *this; } constexpr modint operator-() const { return modint(-x); } constexpr modint operator+(const modint &p) const { return modint(*this) += p; } constexpr modint operator-(const modint &p) const { return modint(*this) -= p; } constexpr modint operator*(const modint &p) const { return modint(*this) *= p; } constexpr modint operator/(const modint &p) const { return modint(*this) /= p; } constexpr bool operator==(const modint &p) const { return x == p.x; } constexpr bool operator!=(const modint &p) const { return x != p.x; } constexpr bool operator!() const { return !x; } // constexpr bool operator>(const modint &p) const { return x > p.x; } // constexpr bool operator<(const modint &p) const { return x < p.x; } // constexpr bool operator>=(const modint &p) const { return x >= p.x; } // constexpr bool operator<=(const modint &p) const { return x <= p.x; } constexpr static modint inverse(const modint &p) { int a = p.x, b = mod, u = 1, v = 0; while(b > 0) { int t = a / b; a -= t * b; a ^= b ^= a ^= b; u -= t * v; u ^= v ^= u ^= v; } return modint(u); } constexpr static modint pow(modint p, int_fast64_t e) { if(!e) return 1; if(e < 0) e = (e % (mod - 1) + mod - 1) % (mod - 1); return pow(p * p, e >> 1) * (e & 1 ? p : 1); } friend ostream &operator<<(ostream &s, const modint &p) { return s << p.x; } friend istream &operator>>(istream &s, modint &p) { uint_fast64_t x; p = modint((s >> x,x)); return s; } }; namespace FFT { template vector> fft(vector> x, bool inverse = false) { size_t n = x.size(),mask = n - 1; //"n" must be a power of two. static vector> tmp; tmp.resize(n); for(size_t i = n >> 1; i; i >>= 1) { Real theta = Pi * 2 * i * (inverse ? -1 : 1) / n; complex zeta(cos(theta),sin(theta)); complex powzeta = 1; for(size_t j = 0; j < n; j += i) { for(size_t k = 0; k < i; ++k) { tmp[j + k] = x[k + (mask & j << 1)] + powzeta * x[k + (mask & i + (j << 1))]; } powzeta *= zeta; } swap(x,tmp); } if(inverse) for(size_t i = 0; i < n; ++i) x[i] /= n; return x; } template vector conv(const vector &a, const vector &b) { size_t n = 1; while(n + 1 < a.size() + b.size()) n <<= 1; vector> x(n),y(n); for(size_t i = 0; i != a.size(); ++i) x[i].real(a[i]); for(size_t i = 0; i != b.size(); ++i) x[i].imag(b[i]); x = fft(x,false); for(int i = 0; i < n; ++i) { int j = i ? n - i : 0; y[i] = (x[i] + conj(x[j])) * (x[i] - conj(x[j])) * complex(0,-.25); } y = fft(y,true); vector c(n); for(size_t i = 0; i < n; ++i) c[i] = y[i].real(); return c; } template <> vector conv(const vector &a, const vector &b) { size_t n = 1; while(n + 1 < a.size() + b.size()) n <<= 1; vector> x(n),y(n); for(size_t i = 0; i != a.size(); ++i) x[i].real(a[i]); for(size_t i = 0; i != b.size(); ++i) x[i].imag(b[i]); x = fft(x,false); for(int i = 0; i < n; ++i) { int j = i ? n - i : 0; y[i] = (x[i] + conj(x[j])) * (x[i] - conj(x[j])) * complex(0,-.25); } y = fft(y,true); vector c(n); for(size_t i = 0; i < n; ++i) c[i] = round(y[i].real()); return c; } template <> vector conv(const vector &a, const vector &b) { size_t n = 1; while(n + 1 < a.size() + b.size()) n <<= 1; vector> x(n), y(n); for(size_t i = 0; i != a.size(); ++i) x[i].real(a[i]); for(size_t i = 0; i != b.size(); ++i) x[i].imag(b[i]); x = fft(x,false); for(int i = 0; i < n; ++i) { int j = i ? n - i : 0; y[i] = (x[i] + conj(x[j])) * (x[i] - conj(x[j])) * complex(0,-.25); } y = fft(y,true); vector c(n); for(size_t i = 0; i < n; ++i) c[i] = round(y[i].real()); return c; } } using mint=modint<1000000007>; int n; int a[1<<17]; void solve() { mint ans=1; for(i64 i=n-1,r=0; i>=0; r+=a[i--]) { ans*=mint::pow(a[i],r); } vector cnt(100001); for(int i=0; i double { return y*log(x)+log(x+y); }; if(f(*l,*p)>f(*p,*r)) { ans/=*r+*p; ans/=mint::pow(*p,*r); } else { ans/=*l+*p; ans/=mint::pow(*l,*p); } } cout<>n; rep(i,n) cin>>a[i]; solve(); }