// includes #include // macros #define pb emplace_back #define mk make_pair #define pq priority_queue #define FOR(i, a, b) for(int i=(a);i<(b);++i) #define rep(i, n) FOR(i, 0, n) #define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--) #define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr) #define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr) #define vrep(v, i) for(int i = 0; i < (v).size(); i++) #define all(x) (x).begin(),(x).end() #define sz(x) ((int)(x).size()) #define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end()) #define FI first #define SE second #define bit(n) (1LL<<(n)) #define INT(n) int n; cin >> n; #define LL(n) ll n; cin >> n; #define DOUBLE(n) double n; cin >> n; using namespace std; template bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;} template bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;} template istream &operator>>(istream &is, vector &vec){for(auto &v: vec)is >> v; return is;} template ostream &operator<<(ostream &os, const vector& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;} template ostream &operator<<(ostream &os, const set& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const unordered_set& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const multiset& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const unordered_multiset& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const pair &p){os << p.first << " " << p.second; return os;} template ostream &operator<<(ostream &os, const map &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;} template ostream &operator<<(ostream &os, const unordered_map &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;} // types using ll = long long int; using P = pair; using Pli = pair; using Pil = pair; using Pll = pair; using Pdd = pair; using cd = complex; // constants const int inf = 1e9; const ll linf = 1LL << 50; const double EPS = 1e-10; const int mod = 1e9 + 7; const int dx[4] = {-1, 0, 1, 0}; const int dy[4] = {0, -1, 0, 1}; // solve struct Tree{ int n = 0; vector> edges; vector b, e; vector v; Tree(){} Tree(int n): n(n){ edges.resize(n); b.resize(n); e.resize(n); v.reserve(2 * n - 1); } void adde(int from, int to){ edges[from].emplace_back(to); } void dfs(int i){ v.emplace_back(i); b[i] = int(v.size()) - 1; for(auto c: edges[i]){ if(b[c] == -1)dfs(c); v.emplace_back(i); } e[i] = int(v.size()) - 1; } void build(int r = 0){ b.assign(n, -1); e.assign(n, -1); v.resize(0); dfs(r); } }; struct Tree2{ int n = 0, m = 0; vector> edge; vector> par; vector vis; vector h; Tree2(){} Tree2(int n): n(n){ while((1LL<(n, 0)); vis.resize(n, false); h.resize(n); } void adde(int from, int to){ edge[from].emplace_back(to); } void dfs(int i){ vis[i] = true; for(auto e: edge[i]){ if(!vis[e]){ par[0][e] = i; h[e] = h[i] + 1; dfs(e); } } } void build(){ fill(vis.begin(), vis.end(), false); fill(h.begin(), h.end(), 0); par[0][0] = 0; h[0] = 0; dfs(0); for(int i = 1; i <= m; i++){ for(int j = 0; j < n; j++){ par[i][j] = par[i-1][par[i-1][j]]; } } } int go_up(int u, int k){ int i = 0; while(k){ if(k % 2 == 1){ u = par[i][u]; } i++; k /= 2; } return u; } int lca(int u, int v){ if(h[u] > h[v])u = go_up(u, h[u] - h[v]); if(h[u] < h[v])v = go_up(v, h[v] - h[u]); if(u == v)return u; int ld = 0, rd = n; while(rd - ld > 1){ int k = (rd + ld) / 2; int uk = go_up(u, k); int vk = go_up(v, k); if(uk == vk)rd = k; else ld = k; } return go_up(u, rd); } }; template struct LazySegmentTree_ { function f; function h; function p; int n; T def; E l_def; vector vec; vector lazy; LazySegmentTree_(){} LazySegmentTree_(int n_, function f_, T def_, function h_, E l_def_, function p_, vector v=vector()){ f = f_; h = h_; p = p_; def = def_; l_def = l_def_; // initialize vector n = 1; while(n < n_){ n *= 2; } vec = vector(2*n-1, def); lazy = vector(2*n-1, l_def); // initialize segment tree for(int i = 0; i < v.size(); i++){ vec[i + n - 1] = v[i]; } for(int i = n - 2; i >= 0; i--){ vec[i] = f(vec[2*i+1], vec[2*i+2]); } } void eval(int k, int len){ if(lazy[k] != l_def){ if(k < n - 1){ lazy[2*k+1] = h(lazy[2*k+1], lazy[k]); lazy[2*k+2] = h(lazy[2*k+2], lazy[k]); } vec[k] = p(vec[k], lazy[k], len); lazy[k] = l_def; } } E update(int a, int b, const E &val, int k, int l, int r){ eval(k, r - l); if(r <= a || b <= l){ return vec[k]; }else if(a <= l && r <= b){ lazy[k] = h(lazy[k], val); eval(k, r - l); return vec[k]; }else{ return vec[k] = f(update(a, b, val, 2*k+1, l, (l+r)/2), update(a, b, val, 2*k+2, (l+r)/2, r)); } } E update(int a, int b, E val){ return update(a, b, val, 0, 0, n); } // [l, r) -> [a, b) (at k) T query(int a, int b, int k, int l, int r){ eval(k, r - l); if(r <= a || b <= l)return def; if(a <= l && r <= b)return vec[k]; T ld = query(a, b, 2*k+1, l, (l+r)/2); T rd = query(a, b, 2*k+2, (l+r)/2, r); return f(ld, rd); } T query(int a, int b){ return query(a, b, 0, 0, n); } }; template using LazySegmentTree = struct LazySegmentTree_; using LazySegmentTreeI = LazySegmentTree; using LazySegmentTreeL = LazySegmentTree; int main(int argc, char const* argv[]) { ios_base::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(20); INT(n); Tree t(n); Tree2 t2(n); rep(i, n - 1){ INT(u); INT(v); u--; v--; t.adde(u, v); t.adde(v, u); t2.adde(u, v); t2.adde(v, u); } t.build(); t2.build(); LazySegmentTreeL seg = LazySegmentTreeL(2 * n, [](ll a, ll b){return a + b;}, 0, [](ll a, ll b){return a + b;}, 0, [](ll a, ll b, int c){return a + b * c;}, vector()); INT(q); rep(i, q){ INT(a); INT(b); a--; b--; int l = t2.lca(a, b); seg.update(0, t.b[a] + 1, 1); seg.update(0, t.b[b] + 1, 1); seg.update(0, t.b[l] + 1, -2); seg.update(t.b[l], t.b[l] + 1, 1); /*rep(j, n){ cout << seg.query(t.b[j], t.b[j] + 1) - seg.query(t.e[j] + 1, t.e[j] + 2) << "\n "[j + 1 != n]; }*/ } ll res = 0; rep(i, n){ ll tmp = seg.query(t.b[i], t.b[i] + 1) - seg.query(t.e[i] + 1, t.e[i] + 2); res += tmp * (tmp + 1) / 2; } cout << res << endl; return 0; }