#include using namespace std; using ll = long long; template using vec = vector; template using vvec = vector>; constexpr ll mod = 1e9+7; struct mint { ll x; mint(ll x=0):x((x%mod+mod)%mod){} friend ostream &operator<<(ostream& os,const mint& a){ return os << a.x; } friend istream &operator>>(istream& is,mint& a){ ll t; is >> t; a = mint(t); return (is); } mint& operator+=(const mint a) { if ((x += a.x) >= mod) x -= mod; return *this; } mint& operator-=(const mint a) { if ((x += mod-a.x) >= mod) x -= mod; return *this; } mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this; } mint operator+(const mint a) const { mint res(*this); return res+=a; } mint operator-(const mint a) const { mint res(*this); return res-=a; } mint operator*(const mint a) const { mint res(*this); return res*=a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t>>1); a *= a; if (t&1) a *= *this; return a; } // for prime mod mint inv() const { return pow(mod-2); } mint& operator/=(const mint a) { return (*this) *= a.inv(); } mint operator/(const mint a) const { mint res(*this); return res/=a; } }; int main(){ cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; vvec g(N); vec indeg(N); for(int i=0;i> a >> b; a--; b--; g[a].push_back(b); indeg[b]++; } mint ans = 0; vec s(N); vec val(N); auto dfs = [&](auto&& self,int cur,int par)->void{ s[cur] = 1; for(auto& to:g[cur]) if(to!=par){ self(self,to,cur); s[cur] += s[to]; val[cur] += val[to]; } val[cur] += s[cur]-1; ans += val[cur]; }; for(int i=0;i