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) {
  }
}