#include using namespace std; const long long MOD=1000000007; // const long long MOD=998244353; #define LOCAL #pragma region Macros typedef long long ll; typedef __int128_t i128; typedef unsigned int uint; typedef unsigned long long ull; #define ALL(x) (x).begin(),(x).end() const int INF=1e9; const long long IINF=1e18; const int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1}; const char dir[4]={'D','R','U','L'}; template istream &operator>>(istream &is,vector &v){ for (T &x:v) is >> x; return is; } template ostream &operator<<(ostream &os,const vector &v){ for (int i=0;i ostream &operator<<(ostream &os,const pair &p){ os << '(' << p.first << ',' << p.second << ')'; return os; } template ostream&operator<<(ostream &os,const tuple &t){ os << '(' << get<0>(t) << ',' << get<1>(t) << ',' << get<2>(t) << ')'; return os; } template ostream&operator<<(ostream &os,const tuple &t){ os << '(' << get<0>(t) << ',' << get<1>(t) << ',' << get<2>(t) << ',' << get<3>(t) << ')'; return os; } template ostream &operator<<(ostream &os,const map &m){ os << '{'; for (auto itr=m.begin();itr!=m.end();){ os << '(' << itr->first << ',' << itr->second << ')'; if (++itr!=m.end()) os << ','; } os << '}'; return os; } template ostream &operator<<(ostream &os,const unordered_map &m){ os << '{'; for (auto itr=m.begin();itr!=m.end();){ os << '(' << itr->first << ',' << itr->second << ')'; if (++itr!=m.end()) os << ','; } os << '}'; return os; } template ostream &operator<<(ostream &os,const set &s){ os << '{'; for (auto itr=s.begin();itr!=s.end();){ os << *itr; if (++itr!=s.end()) os << ','; } os << '}'; return os; } template ostream &operator<<(ostream &os,const multiset &s){ os << '{'; for (auto itr=s.begin();itr!=s.end();){ os << *itr; if (++itr!=s.end()) os << ','; } os << '}'; return os; } template ostream &operator<<(ostream &os,const unordered_set &s){ os << '{'; for (auto itr=s.begin();itr!=s.end();){ os << *itr; if (++itr!=s.end()) os << ','; } os << '}'; return os; } template ostream &operator<<(ostream &os,const deque &v){ for (int i=0;i void debug_out(Head&& head,Tail&&... tail){ cerr << head; if (sizeof...(Tail)>0) cerr << ", "; debug_out(move(tail)...); } #ifdef LOCAL #define debug(...) cerr << " ";\ cerr << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << '\n';\ cerr << " ";\ debug_out(__VA_ARGS__) #else #define debug(...) 42 #endif template T gcd(T x,T y){return y!=0?gcd(y,x%y):x;} template T lcm(T x,T y){return x/gcd(x,y)*y;} template inline bool chmin(T1 &a,T2 b){ if (a>b){a=b; return true;} return false; } template inline bool chmax(T1 &a,T2 b){ if (a class modint{ using i64=int64_t; using u32=uint32_t; using u64=uint64_t; public: u32 v; constexpr modint(const i64 x=0) noexcept :v(x<0?mod-1-(-(x+1)%mod):x%mod){} constexpr u32 &value() noexcept {return v;} constexpr const u32 &value() const noexcept {return v;} constexpr modint operator+(const modint &rhs) const noexcept {return modint(*this)+=rhs;} constexpr modint operator-(const modint &rhs) const noexcept {return modint(*this)-=rhs;} constexpr modint operator*(const modint &rhs) const noexcept {return modint(*this)*=rhs;} constexpr modint operator/(const modint &rhs) const noexcept {return modint(*this)/=rhs;} constexpr modint &operator+=(const modint &rhs) noexcept { v+=rhs.v; if (v>=mod) v-=mod; return *this; } constexpr modint &operator-=(const modint &rhs) noexcept { if (v0){ if (exp&1) res*=self; self*=self; exp>>=1; } return res; } constexpr modint &operator++() noexcept {if (++v==mod) v=0; return *this;} constexpr modint &operator--() noexcept {if (v==0) v=mod; return --v,*this;} constexpr modint operator++(int) noexcept {modint t=*this; return ++*this,t;} constexpr modint operator--(int) noexcept {modint t=*this; return --*this,t;} constexpr modint operator-() const noexcept {return modint(mod-v);} template friend constexpr modint operator+(T x,modint y) noexcept {return modint(x)+y;} template friend constexpr modint operator-(T x,modint y) noexcept {return modint(x)-y;} template friend constexpr modint operator*(T x,modint y) noexcept {return modint(x)*y;} template friend constexpr modint operator/(T x,modint y) noexcept {return modint(x)/y;} constexpr bool operator==(const modint &rhs) const noexcept {return v==rhs.v;} constexpr bool operator!=(const modint &rhs) const noexcept {return v!=rhs.v;} constexpr bool operator!() const noexcept {return !v;} friend istream &operator>>(istream &s,modint &rhs) noexcept { i64 v; rhs=modint{(s>>v,v)}; return s; } friend ostream &operator<<(ostream &s,const modint &rhs) noexcept { return s<; int main(){ cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; vector A(N); cin >> A; vector dp(N,0); vector> sum(MAX,vector(MAX,0)); dp[0]=1; for (int i=0;i