#include using namespace std; #include using namespace atcoder; #define rep(i,n) for (int i = 0; i < (n); i++) #define REP(i,a,b) for(int i=(a);i<(b);i++) #define all(v) begin(v),end(v) #define rall(v) rbegin(v),rend(v) #define fi first #define se second #define re0 return 0 template inline bool chmax(A &a, B b) { if (a inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; } using ll = long long; using pii = pair; using pll = pair; using tup = tuple; using cp = complex; constexpr ll inf = 2e9; constexpr ll llinf = 9e18; constexpr ll MOD = 998244353; //constexpr ll MOD = 1000000007; const double pai = acos(-1); /** * @brief https://tkmst201.github.io/Library/Mathematics/ModInt.hpp */ template struct ModInt { static_assert(M > 0); using value_type = int; using calc_type = std::int_fast64_t; private: value_type val_; public: constexpr ModInt(calc_type val = 0) : val_(val % M + (val >= 0 ? 0 : M)) {} constexpr value_type val() const noexcept { return val_; } constexpr static decltype(M) mod() noexcept { return M; } explicit constexpr operator bool() const noexcept { return val_; } constexpr bool operator !() const noexcept { return !static_cast(*this); } constexpr ModInt operator +() const noexcept { return *this; } constexpr ModInt operator -() const noexcept { return ModInt(val_ == 0 ? 0 : M - val_); } constexpr ModInt operator ++(int) noexcept { ModInt res = *this; ++*this; return res; } constexpr ModInt operator --(int) noexcept { ModInt res = *this; --*this; return res; } constexpr ModInt & operator ++() noexcept { val_ = val_ + 1 == M ? 0 : val_ + 1; return *this; } constexpr ModInt & operator --() noexcept { val_ = val_ == 0 ? M - 1 : val_ - 1; return *this; } constexpr ModInt & operator +=(const ModInt & rhs) noexcept { val_ += val_ < M - rhs.val_ ? rhs.val_ : rhs.val_ - M; return *this; } constexpr ModInt & operator -=(const ModInt & rhs) noexcept { val_ += val_ >= rhs.val_ ? -rhs.val_ : M - rhs.val_; return *this; } constexpr ModInt & operator *=(const ModInt & rhs) noexcept { val_ = static_cast(val_) * rhs.val_ % M; return *this; } constexpr ModInt & operator /=(const ModInt & rhs) noexcept { return *this *= rhs.inv(); } friend constexpr ModInt operator +(const ModInt & lhs, const ModInt & rhs) noexcept { return ModInt(lhs) += rhs; } friend constexpr ModInt operator -(const ModInt & lhs, const ModInt & rhs) noexcept { return ModInt(lhs) -= rhs; } friend constexpr ModInt operator *(const ModInt & lhs, const ModInt & rhs) noexcept { return ModInt(lhs) *= rhs; } friend constexpr ModInt operator /(const ModInt & lhs, const ModInt & rhs) noexcept { return ModInt(lhs) /= rhs; } friend constexpr bool operator ==(const ModInt & lhs, const ModInt & rhs) noexcept { return lhs.val_ == rhs.val_; } friend constexpr bool operator !=(const ModInt & lhs, const ModInt & rhs) noexcept { return !(lhs == rhs); } friend std::ostream & operator <<(std::ostream & os, const ModInt & rhs) { return os << rhs.val_; } friend std::istream & operator >>(std::istream & is, ModInt & rhs) { calc_type x; is >> x; rhs = ModInt(x); return is; } constexpr ModInt pow(calc_type n) const noexcept { ModInt res = 1, x = val_; if (n < 0) { x = x.inv(); n = -n; } while (n) { if (n & 1) res *= x; x *= x; n >>= 1; } return res; } constexpr ModInt inv() const noexcept { value_type a = val_, a1 = 1, b = M, b1 = 0; while (b > 0) { const value_type q = a / b; value_type tmp = a - q * b; a = b; b = tmp; tmp = a1 - q * b1; a1 = b1; b1 = tmp; } assert(a == 1); if (a1 < 0) a1 += M; return a1; } }; using mint = ModInt; mint ans=0; vector> g; ll n; ll cnt=0; void dfs(int v,int p=-1){ cnt++; for(int u:g[v]){ if(u==p)continue; dfs(u,v); } cnt--; if(cnt!=0)ans+=cnt*(cnt-1)/2+(n-cnt)*(n-cnt-1)/2; } int main() { //cout<>n; g.resize(n); rep(i,n-1){ int a,b;cin>>a>>b; a--;b--; g[a].push_back(b); g[b].push_back(a); } dfs(0); ans/=(n-1)*n*(n-1)/2; cout<