#include #define rep(i,n) for (int i = 0; i < (n); ++i) #define rrep(i,n) for (int i = (n)-1; i >= 0; i--) #define rep2(i,s,n) for (int i = (s); i < (n); ++i) #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define pb push_back #define eb emplace_back #define vi vector #define vvi vector> #define vl vector #define vvl vector> #define vd vector #define vs vector #define vc vector #define vb vector #define vp vector

using namespace std; using ll = long long; using P = pair; using LP = pair; template istream& operator>>(istream &is,pair &p) { return is >> p.first >> p.second; } template ostream& operator<<(ostream &os,const pair &p) { return os<<'{'< istream& operator>>(istream &is,vector &v) { for(T &t:v){is>>t;} return is; } template ostream& operator<<(ostream &os,const vector &v) { os<<'[';rep(i,v.size())os< bool chmin(T& a,T b) {if(a > b){a = b; return true;} return false;} template bool chmax(T& a,T b) {if(a < b){a = b; return true;} return false;} const int inf = 1001001001; const ll linf = 1001001001001001001; const int mod = 1000000007; //const int mod = 998244353; struct mint { ll x; mint(ll x=0):x((x%mod+mod)%mod){} mint operator-() const { return mint(-x);} mint& operator+=(const mint& a) { if ((x += a.x) >= mod) x -= mod; return *this;} mint& operator++() { return *this += mint(1); } mint& operator-=(const mint& a) { if ((x += mod-a.x) >= mod) x -= mod; return *this; } mint& operator--() { return *this -= mint(1); } 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 { mint res = mint(1),a(*this); while(t > 0) { if(t&1) res *= a; t >>= 1; a *= a; } return res; } // 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; } }; ostream& operator<<(ostream& os,const mint& m) { return os << m.x; } vvi G; vector ans; vi sz; void dfs(int v,int p) { for(int u : G[v]) { if(u == p) continue; dfs(u,v); sz[v] += sz[u]; ans[v] += ans[u]; } ans[v] += sz[v]; sz[v]++; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int n; cin >> n; G.resize(n); vi in(n); rep(_,n-1) { int a,b; cin >> a >> b; a--; b--; G[a].pb(b); G[b].pb(a); in[b]++; } ans.resize(n); sz.resize(n); rep(i,n) if(!in[i]) dfs(i,-1); cout << accumulate(all(ans),mint(0)) << endl; }