class UnionFindVerSize():
    def __init__(self, N,init_P,init_S):
        self._parent = [n for n in range(0, N)]
        self.P_sum = [0 for i in range(N)]
        for i in range(N):
            if init_P[i]:
                self.P_sum[i] = 1/init_P[i]
        self.S_sum = [init_S[i] for i in range(N)]
        self._size = [1]*N
        self.group = N
        self.ans = 0
        for i in range(N):
            if self.P_sum[i]!=0:
                self.ans += self.S_sum[i]**2/self.P_sum[i]

    def find_root(self, x):
        if self._parent[x] == x: return x
        self._parent[x] = self.find_root(self._parent[x])
        stack = [x]
        while self._parent[stack[-1]]!=stack[-1]:
            stack.append(self._parent[stack[-1]])
        for v in stack:
            self._parent[v] = stack[-1]
        return self._parent[x]

    def unite(self, x, y):
        gx = self.find_root(x)
        gy = self.find_root(y)
        if gx == gy: return

        self.group -= 1

        if self._size[gx] >= self._size[gy]:
            gx,gy = gy,gx

        self._parent[gx] = gy
        self._size[gy] += self._size[gx]

        if self.P_sum[gx]!=0:
            self.ans -= self.S_sum[gx]**2 / self.P_sum[gx]
        if self.P_sum[gy]!=0:
            self.ans -= self.S_sum[gy]**2 / self.P_sum[gy]

        self.S_sum[gy] += self.S_sum[gx]

        if self.P_sum[gx]!=0 and self.P_sum[gy]!=0:
            self.P_sum[gy] += self.P_sum[gx]
        else:
            self.P_sum[gy] = 0

        if self.P_sum[gy]!=0:
            self.ans += self.S_sum[gy]**2 / self.P_sum[gy]

    def get_size(self, x):
        return self._size[self.find_root(x)]

    def is_same_group(self, x, y):
        return self.find_root(x) == self.find_root(y)

import sys

input = sys.stdin.readline

N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
P = list(map(int,input().split()))

S = [A[i]-B[i] for i in range(N)]

uf = UnionFindVerSize(N,P,S)
ans = []
for _ in range(int(input())):
    x,y = map(int,input().split())
    uf.unite(x-1,y-1)
    ans.append(uf.ans)

print(*ans,sep="\n")