using System; using System.Collections.Generic; using System.Linq; using System.IO; using System.Runtime.CompilerServices; using System.Text; using System.Diagnostics; using System.Numerics; using static System.Console; using static System.Convert; using static System.Math; using static Template; using Pi = Pair; class Solver { List[] g; int[] imos; long res=0; public void Solve(Scanner sc) { var N = sc.Int; g = Create(N, () => new List()); var hl = new HLDecomposition(N); for (int i = 0; i < N-1; i++) { int u, v; sc.Make(out u, out v);u--;v--; hl.AddEdge(u, v);g[u].Add(v);g[v].Add(u); } hl.Build(); imos = new int[N]; var Q = sc.Int; while (Q-- > 0) { int a, b; sc.Make(out a, out b);a--;b--; int lca = hl.LCA(a, b); imos[a]++; imos[b]++; imos[lca]--; if (lca != 0) imos[hl.par[lca]]--; } dfs(0, -1); Console.WriteLine(res); } void dfs(int i,int p) { foreach (var e in g[i]) { if (e == p) continue; dfs(e, i); imos[i] += imos[e]; } res += imos[i] * (imos[i] + 1L) / 2; } } class HLDecomposition { List[] G; public int this[int i] => vertex[i]; public int[] vertex, head, subtreeSize, par, dep, rev, right; public HLDecomposition(int sz) { G = Create(sz, () => new List()); vertex = Create(sz, () => -1); head = new int[sz]; subtreeSize = new int[sz]; par = Create(sz, () => -1); dep = new int[sz]; rev = new int[sz]; right = new int[sz]; } public void AddEdge(int u,int v) { G[u].Add(v); G[v].Add(u); } public void Build(int root = 0) { int c = 0, pos = 0; head[root] = root; CalcSubtreeSize(root); Decomposition(root, ref pos); } void CalcSubtreeSize(int idx) { for (int i = 0; i < G[idx].Count; i++) if (G[idx][i] == par[idx]) { G[idx].swap(i, G[idx].Count - 1); break; } if (par[idx] != -1) G[idx].PopBack(); for (int i = 0; i < G[idx].Count; i++) { int to = G[idx][i]; par[to] = idx; dep[to] = dep[idx] + 1; CalcSubtreeSize(to); subtreeSize[idx] += subtreeSize[to]; if (subtreeSize[to] > subtreeSize[G[idx][0]]) G[idx].swap(i, 0); } subtreeSize[idx]++; } void Decomposition(int idx,ref int pos) { vertex[idx] = pos++; rev[vertex[idx]] = idx; for (int i = 0; i < G[idx].Count; i++) { int to = G[idx][i]; head[to] = (i == 0 ? head[idx] : to); Decomposition(to, ref pos); } right[idx] = pos; } public int LCA(int u,int v) { while (true) { if (vertex[u] > vertex[v]) swap(ref u, ref v); if (head[u] == head[v]) return u; v = par[head[v]]; } } public int Distance(int u, int v) => dep[u] + dep[v] - 2 * dep[LCA(u, v)]; public void For_each(int u, int v, Action f) { while (true) { if (vertex[u] > vertex[v]) swap(ref u, ref v); f(Max(vertex[head[v]], vertex[u]), vertex[v] + 1); if (head[u] != head[v]) v = par[head[v]]; else break; } } public void For_each_Edge(int u,int v,Action f) { while (true) { if (vertex[u] > vertex[v]) swap(ref u, ref v); if (head[u] != head[v]) { f(vertex[head[v]], vertex[v]+1); v = par[head[v]]; } else { if (u != v) f(vertex[u] + 1, vertex[v] + 1); break; } } } public void SubtreeQuery(int v, Action f) => f(vertex[v], right[v]); } #region Template public static class Template { static void Main(string[] args) { Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false }); new Solver().Solve(new Scanner()); Console.Out.Flush(); } [MethodImpl(MethodImplOptions.AggressiveInlining)] public static bool chmin(ref T a, T b) where T : IComparable { if (a.CompareTo(b) > 0) { a = b; return true; } return false; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public static bool chmax(ref T a, T b) where T : IComparable { if (a.CompareTo(b) < 0) { a = b; return true; } return false; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public static void swap(ref T a, ref T b) { var t = b; b = a; a = t; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public static void swap(this IList A, int i, int j) { var t = A[i]; A[i] = A[j]; A[j] = t; } public static T[] Create(int n, Func f) { var rt = new T[n]; for (var i = 0; i < rt.Length; ++i) rt[i] = f(); return rt; } public static T[] Create(int n, Func f) { var rt = new T[n]; for (var i = 0; i < rt.Length; ++i) rt[i] = f(i); return rt; } public static IEnumerable Shuffle(this IEnumerable A) => A.OrderBy(v => Guid.NewGuid()); public static int CompareTo(this T[] A, T[] B, Comparison cmp = null) { cmp = cmp ?? Comparer.Default.Compare; for (var i = 0; i < Min(A.Length, B.Length); i++) { int c = cmp(A[i], B[i]); if (c > 0) return 1; else if (c < 0) return -1; } if (A.Length == B.Length) return 0; if (A.Length > B.Length) return 1; else return -1; } public static int MaxElement(this IList A, Comparison cmp = null) { cmp = cmp ?? Comparer.Default.Compare; T max = A[0]; int rt = 0; for (int i = 1; i < A.Count; i++) if (cmp(max, A[i]) < 0) { max = A[i]; rt = i; } return rt; } public static T PopBack(this List A) { var v = A[A.Count - 1]; A.RemoveAt(A.Count - 1); return v; } public static void Fail(T s) { Console.WriteLine(s); Console.Out.Close(); Environment.Exit(0); } } public class Scanner { public string Str => Console.ReadLine().Trim(); public int Int => int.Parse(Str); public long Long => long.Parse(Str); public double Double => double.Parse(Str); public int[] ArrInt => Str.Split(' ').Select(int.Parse).ToArray(); public long[] ArrLong => Str.Split(' ').Select(long.Parse).ToArray(); public char[][] Grid(int n) => Create(n, () => Str.ToCharArray()); public int[] ArrInt1D(int n) => Create(n, () => Int); public long[] ArrLong1D(int n) => Create(n, () => Long); public int[][] ArrInt2D(int n) => Create(n, () => ArrInt); public long[][] ArrLong2D(int n) => Create(n, () => ArrLong); private Queue q = new Queue(); [MethodImpl(MethodImplOptions.AggressiveInlining)] public T Next() { if (q.Count == 0) foreach (var item in Str.Split(' ')) q.Enqueue(item); return (T)Convert.ChangeType(q.Dequeue(), typeof(T)); } public void Make(out T1 v1) => v1 = Next(); public void Make(out T1 v1, out T2 v2) { v1 = Next(); v2 = Next(); } public void Make(out T1 v1, out T2 v2, out T3 v3) { Make(out v1, out v2); v3 = Next(); } public void Make(out T1 v1, out T2 v2, out T3 v3, out T4 v4) { Make(out v1, out v2, out v3); v4 = Next(); } public void Make(out T1 v1, out T2 v2, out T3 v3, out T4 v4, out T5 v5) { Make(out v1, out v2, out v3, out v4); v5 = Next(); } public void Make(out T1 v1, out T2 v2, out T3 v3, out T4 v4, out T5 v5, out T6 v6) { Make(out v1, out v2, out v3, out v4, out v5); v6 = Next(); } //public (T1, T2) Make() { Make(out T1 v1, out T2 v2); return (v1, v2); } //public (T1, T2, T3) Make() { Make(out T1 v1, out T2 v2, out T3 v3); return (v1, v2, v3); } //public (T1, T2, T3, T4) Make() { Make(out T1 v1, out T2 v2, out T3 v3, out T4 v4); return (v1, v2, v3, v4); } } public class Pair : IComparable> { public T1 v1; public T2 v2; public Pair() { } public Pair(T1 v1, T2 v2) { this.v1 = v1; this.v2 = v2; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public int CompareTo(Pair p) { var c = Comparer.Default.Compare(v1, p.v1); if (c == 0) c = Comparer.Default.Compare(v2, p.v2); return c; } public override string ToString() => $"{v1.ToString()} {v2.ToString()}"; public void Deconstruct(out T1 a, out T2 b) { a = v1; b = v2; } } public class Pair : Pair, IComparable> { public T3 v3; public Pair() : base() { } public Pair(T1 v1, T2 v2, T3 v3) : base(v1, v2) { this.v3 = v3; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public int CompareTo(Pair p) { var c = base.CompareTo(p); if (c == 0) c = Comparer.Default.Compare(v3, p.v3); return c; } public override string ToString() => $"{base.ToString()} {v3.ToString()}"; public void Deconstruct(out T1 a, out T2 b, out T3 c) { Deconstruct(out a, out b); c = v3; } } #endregion