import std.conv, std.functional, std.range, std.stdio, std.string; import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons; import core.bitop; class EOFException : Throwable { this() { super("EOF"); } } string[] tokens; string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; } int readInt() { return readToken.to!int; } long readLong() { return readToken.to!long; } real readReal() { return readToken.to!real; } bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } } bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } } int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; } int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); } int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); } // Dijkstra class MinCostFlow(Capa, Cost, Capa CAPA_EPS = 0) { int n, m; int[][] g; int[] as, bs; Capa[] capa; Cost[] cost, pot; Capa tof; Cost toc; this(int n) { this.n = n; m = 0; g = new int[][n]; as = []; bs = []; capa = []; cost = []; } int addEdge(int u, int v, Capa w, Cost c) { debug { // writeln("addEdge ", u, " ", v, " ", w, " ", c); } const i = m; g[u] ~= m; as ~= u; bs ~= v; capa ~= w; cost ~= c; ++m; g[v] ~= m; as ~= v; bs ~= u; capa ~= 0; cost ~= -c; ++m; return i; } bool solve(int source, int sink, Capa flow) { pot = new Cost[n]; pot[] = 0; for (; ; ) { bool cont; foreach (u; 0 .. n) foreach (i; g[u]) if (capa[i] > CAPA_EPS) { const v = bs[i]; if (pot[v] > pot[u] + cost[i]) { pot[v] = pot[u] + cost[i]; cont = true; } } if (!cont) break; } auto dist = new Cost[n]; auto prei = new int[n]; auto vis = new bool[n]; for (tof = 0, toc = 0; tof + CAPA_EPS < flow; ) { /* alias Entry = Tuple!(Cost, "c", int, "u"); BinaryHeap!(Array!Entry, "a > b") que; */ dist[] = -1; prei[] = -1; vis[] = false; dist[source] = 0; prei[source] = -2; /* que.insert(Entry(0, source)); for (; !que.empty(); ) { const c = que.front.c; const u = que.front.u; que.removeFront; if (vis[u]) continue; vis[u] = true; foreach (i; g[u]) if (capa[i] > CAPA_EPS) { const v = bs[i]; if (vis[v]) continue; const cc = c + cost[i] + pot[u] - pot[v]; if (prei[v] == -1 || dist[v] > cc) { dist[v] = cc; prei[v] = i; que.insert(Entry(cc, v)); } } } */ for (; ; ) { int um = -1; foreach (u; 0 .. n) if (!vis[u] && ~dist[u]) { if (!~um || dist[um] > dist[u]) { um = u; } } if (!~um) { break; } vis[um] = true; foreach (i; g[um]) if (capa[i] > CAPA_EPS) { const v = bs[i]; if (!vis[v]) { const cc = dist[um] + cost[i] + pot[um] - pot[v]; if (!~dist[v] || dist[v] > cc) { dist[v] = cc; prei[v] = i; } } } } if (!vis[sink]) return false; Capa f = flow - tof; for (int v = sink; v != source; ) { const i = prei[v]; if (f > capa[i]) f = capa[i]; v = as[i]; } for (int v = sink; v != source; ) { const i = prei[v]; capa[i] -= f; capa[i ^ 1] += f; v = as[i]; } tof += f; toc += f * (dist[sink] - pot[source] + pot[sink]); pot[] += dist[]; } return true; } } int[2] N; int[][2] A, B; int[][][2] G; int[int] cache; int calc(int u0, int p0, int u1, int p1) { const key = u0 | p0 << 8 | u1 << 16 | p1 << 24; auto ptr = key in cache; if (ptr) { return *ptr; } int[2] vsLens; int[][2] vss; foreach (h; 0 .. 2) { const u = (h == 0) ? u0 : u1; const p = (h == 0) ? p0 : p1; foreach (i; G[h][u]) { const v = A[h][i] ^ B[h][i] ^ u; if (v != p) { vss[h] ~= v; } } vsLens[h] = cast(int)(vss[h].length); } auto mcf = new MinCostFlow!(int, int)(2 + vsLens[0] + vsLens[1]); foreach (x; 0 .. vsLens[0]) { mcf.addEdge(0, 2 + x, 1, 0); } foreach (y; 0 .. vsLens[1]) { mcf.addEdge(2 + vsLens[0] + y, 1, 1, 0); } foreach (x; 0 .. vsLens[0]) foreach (y; 0 .. vsLens[1]) { const score = calcSub(vss[0][x], u0, vss[1][y], u1); if (score >= 0) { mcf.addEdge(2 + x, 2 + vsLens[0] + y, 1, -(1 + score)); } } const status = mcf.solve(0, 1, vsLens[0]); const ret = status ? -mcf.toc : -1; return cache[key] = ret; } int[int] cacheSub; int calcSub(int u0, int p0, int u1, int p1) { const key = u0 | p0 << 8 | u1 << 16 | p1 << 24; auto ptr = key in cacheSub; if (ptr) { return *ptr; } int ret = calc(u0, p0, u1, p1); foreach (i; G[1][u1]) { const v1 = A[1][i] ^ B[1][i] ^ u1; if (v1 != p1) { const res = calcSub(u0, p0, v1, u1); if (res >= 0) { chmax(ret, 1 + res); } } } return cacheSub[key] = ret; } void main() { try { for (; ; ) { foreach (h; 0 .. 2) { N[h] = readInt; A[h] = new int[N[h] - 1]; B[h] = new int[N[h] - 1]; foreach (i; 0 .. N[h] - 1) { A[h][i] = readInt - 1; B[h][i] = readInt - 1; } } foreach (h; 0 .. 2) { G[h] = new int[][N[h]]; foreach (i; 0 .. N[h] - 1) { G[h][A[h][i]] ~= i; G[h][B[h][i]] ~= i; } } cache.clear; cacheSub.clear; int ans = -1; foreach (r0; 0 .. N[0]) foreach (r1; 0 .. N[1]) { chmax(ans, calc(r0, N[0], r1, N[1])); } writeln(ans); } } catch (EOFException e) { } }