#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
inline string tostr(const T &x) {
  stringstream ss;
  ss << x;
  return ss.str();
}
inline long long parse(const string &s) {
  stringstream ss(s);
  long long x;
  ss >> x;
  return x;
}
const double EPS = 1e-10;
const int INF = 1000 * 1000 * 1000;
const long long LINF = INF * 1ll * INF;
const double DINF = 1e200;
const double PI = 3.1415926535897932384626433832795l;
int gcd(int a, int b) { return a ? gcd(b % a, a) : b; }
long long gcd(long long a, long long b) { return a ? gcd(b % a, a) : b; }
long long gcdex(long long a, long long b, long long &x, long long &y) {
  if (!a) {
    x = 0, y = 1;
    return b;
  }
  long long k = b / a;
  long long g = gcdex(b - k * a, a, y, x);
  x -= k * y;
  return g;
}
long long inv(long long a, long long m) {
  long long x, y, g;
  g = gcdex(a, m, x, y);
  return (x % (m / g) + m / g) % m / g;
}
long long crt(long long a1, long long m1, long long a2, long long m2) {
  long long a = (a2 - a1 % m2 + m2) % m2;
  long long x, y, g;
  g = gcdex(m1, m2, x, y);
  if (a % g) return -1;
  long long m = m1 / g * m2;
  x *= a / g;
  x = (x % m2 + m2) % m2;
  long long r = (a1 + x * m1) % m;
  assert(r % m1 == a1 && r % m2 == a2);
  return r;
}
long long powmod(long long a, long long p, long long m) {
  long long r = 1;
  while (p) {
    if (p & 1) r = r * a % m;
    p >>= 1;
    a = a * a % m;
  }
  return r;
}
bool isprime(long long a) {
  if (a <= 1) return false;
  for (long long i = 2; i * i <= a; ++i) {
    if (a % i == 0) return false;
  }
  return true;
}
long long sqrtup(long long a) {
  if (!a) return 0;
  long long x = max(0ll, (long long)sqrt((double)a));
  while (x * x >= a) --x;
  while ((x + 1) * (x + 1) < a) ++x;
  return x + 1;
}
long long isqrt(long long a) {
  long long x = max(0ll, (long long)sqrt((double)a));
  while (x * x > a) --x;
  while ((x + 1) * (x + 1) <= a) ++x;
  return x;
}
template <class T>
ostream &operator<<(ostream &s, const vector<T> &v);
template <class A, class B>
ostream &operator<<(ostream &s, const pair<A, B> &p);
template <class K, class V>
ostream &operator<<(ostream &s, const map<K, V> &m);
template <class T, size_t N>
ostream &operator<<(ostream &s, const array<T, N> &a);
template <class T>
ostream &operator<<(ostream &s, const vector<T> &v) {
  s << '[';
  for (int i = 0; i < (((int)(v).size())); ++i) {
    if (i) s << ',';
    s << v[i];
  }
  s << ']';
  return s;
}
template <class A, class B>
ostream &operator<<(ostream &s, const pair<A, B> &p) {
  s << "(" << p.first << "," << p.second << ")";
  return s;
}
template <class K, class V>
ostream &operator<<(ostream &s, const map<K, V> &m) {
  s << "{";
  bool f = false;
  for (const auto &it : m) {
    if (f) s << ",";
    f = true;
    s << it.first << ": " << it.second;
  }
  s << "}";
  return s;
}
template <class T>
ostream &operator<<(ostream &s, const set<T> &m) {
  s << "{";
  bool f = false;
  for (const auto &it : m) {
    if (f) s << ",";
    f = true;
    s << it;
  }
  s << "}";
  return s;
}
template <class T>
ostream &operator<<(ostream &s, const multiset<T> &m) {
  s << "{";
  bool f = false;
  for (const auto &it : m) {
    if (f) s << ",";
    f = true;
    s << it;
  }
  s << "}";
  return s;
}
template <class T, size_t N>
ostream &operator<<(ostream &s, const array<T, N> &a) {
  s << '[';
  for (int i = 0; i < (((int)(a).size())); ++i) {
    if (i) s << ',';
    s << a[i];
  }
  s << ']';
  return s;
}
template <size_t n, class... T>
struct put1 {
  static ostream &put(ostream &s, const tuple<T...> &t) {
    s << get<sizeof...(T) - n>(t);
    if (n > 1) s << ',';
    return put1<n - 1, T...>::put(s, t);
  }
};
template <class... T>
struct put1<0, T...> {
  static ostream &put(ostream &s, const tuple<T...> &t) { return s; }
};
template <class... T>
ostream &operator<<(ostream &s, const tuple<T...> &t) {
  s << "(";
  put1<sizeof...(T), T...>::put(s, t);
  s << ")";
  return s;
}
ostream &put2(ostream &s, const tuple<> &t) { return s; }
template <class U>
ostream &put2(ostream &s, const tuple<U> &t) {
  return s << get<0>(t);
}
template <class U, class V, class... T>
ostream &put2(ostream &s, const tuple<U, V, T...> &t) {
  return s << t;
}
int main(int argc, char **argv) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, T, Q;
  cin >> n >> T >> Q;
  vector<double> P(n);
  for (int i = 0; i < (n); ++i) cin >> P[i];
  vector<int> L(n);
  for (int i = 0; i < (n); ++i) cin >> L[i];
  vector<int> C(n);
  auto get = [&](int i, int c) { return P[i] * c / (L[i] + c); };
  struct val {
    double x;
    int i, l, c;
    bool operator<(const val &v) const { return x < v.x; }
  };
  priority_queue<val> inq, deq;
  int cnt = 0;
  double sum = 0;
  auto qu = [&](priority_queue<val> &q) {
    while (!q.empty()) {
      val v = q.top();
      if (C[v.i] == v.c && L[v.i] == v.l) return v;
      q.pop();
    }
    return val{-1, -1, -1, -1};
  };
  auto upi = [&](int i) {
    if (C[i]) deq.push(val{get(i, C[i] - 1) - get(i, C[i]), i, L[i], C[i]});
    if (C[i] < L[i])
      inq.push(val{get(i, C[i] + 1) - get(i, C[i]), i, L[i], C[i]});
  };
  for (int i = 0; i < (n); ++i) upi(i);
  auto upc = [&](int i, int d) {
    sum -= get(i, C[i]);
    C[i] += d;
    sum += get(i, C[i]);
    cnt += d;
    upi(i);
  };
  auto upd = [&] {
    while (cnt < T) {
      val v = qu(inq);
      if (v.i == -1) break;
      inq.pop();
      upc(v.i, +1);
    }
    while (true) {
      val v1 = qu(deq);
      val v2 = qu(inq);
      if (v1.i == -1 || v2.i == -1) break;
      if (v1.x + v2.x <= 0 || v1.i == v2.i) break;
      inq.pop();
      deq.pop();
      upc(v1.i, -1);
      upc(v2.i, +1);
    }
  };
  for (int qqq = 0; qqq < (Q); ++qqq) {
    int t, i;
    cin >> t >> i;
    --i;
    sum -= get(i, C[i]);
    if (t == 1)
      ++L[i];
    else
      --L[i];
    sum += get(i, C[i]);
    upi(i);
    if (C[i] > L[i]) upc(i, L[i] - C[i]);
    upd();
    cout.precision(20);
    cout << sum << '\n';
  }
  return 0;
}
