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)); } int root(int[] uf, int u) { return (uf[u] < 0) ? u : (uf[u] = uf.root(uf[u])); } bool connect(int[] uf, int u, int v) { u = uf.root(u); v = uf.root(v); if (u == v) return false; if (uf[u] > uf[v]) swap(u, v); uf[u] += uf[v]; uf[v] = u; return true; } /* minimize \sum_i P[i] x[i]^2 subject to \sum_i x[i] = S if P[i] != 0: T := \sum_i 1/P[i] l = S / T x[i] = l / P[i] min = l^2 \sum_i 1/P[i] = l^2 T = S^2 / T */ void main() { try { for (; ; ) { const N = readInt(); auto A = new real[N]; foreach (u; 0 .. N) { A[u] = readReal(); } auto B = new real[N]; foreach (u; 0 .. N) { B[u] = readReal(); } auto P = new real[N]; foreach (u; 0 .. N) { P[u] = readReal(); } const Q = readInt(); auto X = new int[Q]; auto Y = new int[Q]; foreach (q; 0 .. Q) { X[q] = readInt() - 1; Y[q] = readInt() - 1; } auto hs = new bool[N]; auto ss = new real[N]; auto ts = new real[N]; auto zs = new real[N]; foreach (u; 0 .. N) { hs[u] = (P[u] == 0.0L); ss[u] = A[u] - B[u]; ts[u] = (P[u] == 0.0L) ? 0.0L : (1.0L / P[u]); zs[u] = hs[u] ? 0.0L : (ss[u] * ss[u] / ts[u]); } real ans = zs.sum; auto uf = new int[N]; uf[] = -1; foreach (q; 0 .. Q) { const ru = uf.root(X[q]); const rv = uf.root(Y[q]); if (ru != rv) { ans -= zs[ru]; ans -= zs[rv]; uf.connect(ru, rv); const r = uf.root(ru); hs[r] = hs[ru] || hs[rv]; ss[r] = ss[ru] + ss[rv]; ts[r] = ts[ru] + ts[rv]; zs[r] = hs[r] ? 0.0L : (ss[r] * ss[r] / ts[r]); ans += zs[r]; } writefln("%.10f", ans); } } } catch (EOFException e) { } }