#include <bits/stdc++.h>
using namespace std;
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << '{';
  string sep;
  for (const auto &x : v) os << sep << x, sep = ", ";
  return os << '}';
}
template <typename T, size_t size>
ostream &operator<<(ostream &os, const array<T, size> &arr) {
  os << '{';
  string sep;
  for (const auto &x : arr) os << sep << x, sep = ", ";
  return os << '}';
}
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
void dbg_out() { cerr << endl; }
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
  cerr << ' ' << H;
  dbg_out(T...);
}
using splay_key = int;
struct splay_node {
  splay_node *parent = nullptr, *child[2] = {nullptr, nullptr};
  splay_key key;
  int size = 1;
  int64_t sum = 0;
  static int get_size(splay_node *x) { return x == nullptr ? 0 : x->size; }
  static int64_t get_sum(splay_node *x) { return x == nullptr ? 0 : x->sum; }
  int parent_index() const {
    if (parent == nullptr) return -1;
    return this == parent->child[0] ? 0 : 1;
  }
  void set_child(int index, splay_node *x) {
    child[index] = x;
    if (x != nullptr) x->parent = this;
  }
  void join() {
    size = get_size(child[0]) + get_size(child[1]) + 1;
    sum = get_sum(child[0]) + get_sum(child[1]) + key;
  }
};
auto random_address = [] {
  char *p = new char;
  delete p;
  return uint64_t(p);
};
mt19937_64 splay_rng(chrono::steady_clock::now().time_since_epoch().count() *
                     (random_address() | 1));
int64_t splay_count = 0;
struct splay_tree {
  static const int POOL_SIZE = 10000;
  static vector<splay_node *> node_pool;
  static vector<splay_node *> pointers_to_delete;
  static splay_node *new_node(const splay_key &key) {
    if (node_pool.empty()) {
      splay_node *ptr = new splay_node[POOL_SIZE];
      pointers_to_delete.push_back(ptr);
      for (int i = POOL_SIZE - 1; i >= 0; i--) node_pool.push_back(ptr + i);
    }
    splay_node *node = node_pool.back();
    node_pool.pop_back();
    node->key = key;
    node->join();
    return node;
  }
  static bool _exit_delete_setup;
  static void _delete_pointers() {
    for (splay_node *node : pointers_to_delete) delete[] node;
    pointers_to_delete.clear();
  }
  ~splay_tree() {
    if (!_exit_delete_setup) {
      atexit(_delete_pointers);
      _exit_delete_setup = true;
    }
  }
  splay_node *root = nullptr;
  bool empty() const { return root == nullptr; }
  int size() const { return root == nullptr ? 0 : root->size; }
  splay_node *set_root(splay_node *x) {
    if (x != nullptr) x->parent = nullptr;
    return root = x;
  }
  void rotate_up(splay_node *x, bool x_join = true) {
    splay_node *p = x->parent, *gp = p->parent;
    int index = x->parent_index();
    if (gp == nullptr)
      set_root(x);
    else
      gp->set_child(p->parent_index(), x);
    p->set_child(index, x->child[!index]);
    x->set_child(!index, p);
    p->join();
    if (x_join) x->join();
  }
  void splay(splay_node *x) {
    splay_count++;
    while (x != root) {
      splay_node *p = x->parent;
      if (p != root)
        rotate_up(x->parent_index() == p->parent_index() ? p : x, false);
      rotate_up(x, false);
    }
    x->join();
  }
  static constexpr double SPLAY_RNG_RANGE = double(splay_rng.max()) + 1.0;
  static constexpr double LOG_CONSTANT = 2.0;
  static constexpr double SPLAY_PROBABILITY = 0.25;
  static const int SIZE_CUTOFF = 100;
  void check_splay(splay_node *x, int depth) {
    assert(x != nullptr);
    int n = size(), log_n = 32 - __builtin_clz(n);
    if (depth > LOG_CONSTANT * log_n ||
        (n < SIZE_CUTOFF &&
         double(splay_rng()) < SPLAY_PROBABILITY * SPLAY_RNG_RANGE))
      splay(x);
  }
  pair<splay_node *, int> insert(const splay_key &key,
                                 bool require_unique = false) {
    return insert(new_node(key), require_unique);
  }
  pair<splay_node *, int> insert(splay_node *x, bool require_unique = false) {
    if (root == nullptr) return {set_root(x), 0};
    splay_node *current = root, *prev = nullptr;
    int below = 0, depth = 0;
    while (current != nullptr) {
      prev = current;
      depth++;
      if (current->key < x->key) {
        below += splay_node::get_size(current->child[0]) + 1;
        current = current->child[1];
      } else {
        if (require_unique && !(x->key < current->key)) {
          below += splay_node::get_size(current->child[0]);
          check_splay(current, depth);
          return {current, below};
        }
        current = current->child[0];
      }
    }
    prev->set_child(prev->key < x->key ? 1 : 0, x);
    check_splay(x, depth);
    for (splay_node *node = x; node != nullptr; node = node->parent)
      node->join();
    return {x, below};
  }
  splay_node *begin() {
    if (root == nullptr) return nullptr;
    splay_node *x = root;
    int depth = 0;
    while (x->child[0] != nullptr) {
      x = x->child[0];
      depth++;
    }
    check_splay(x, depth);
    return x;
  }
  splay_node *successor(splay_node *x) const {
    if (x == nullptr) return nullptr;
    if (x->child[1] != nullptr) {
      x = x->child[1];
      while (x->child[0] != nullptr) x = x->child[0];
      return x;
    }
    while (x->parent_index() == 1) x = x->parent;
    return x->parent;
  }
  splay_node *predecessor(splay_node *x) const {
    if (x == nullptr) return nullptr;
    if (x->child[0] != nullptr) {
      x = x->child[0];
      while (x->child[1] != nullptr) x = x->child[1];
      return x;
    }
    while (x->parent_index() == 0) x = x->parent;
    return x->parent;
  }
  splay_node *last() {
    if (root == nullptr) return nullptr;
    splay_node *x = root;
    int depth = 0;
    while (x->child[1] != nullptr) {
      x = x->child[1];
      depth++;
    }
    check_splay(x, depth);
    return x;
  }
  void clear() {
    vector<splay_node *> nodes;
    nodes.reserve(size());
    for (splay_node *node = begin(); node != nullptr; node = successor(node))
      nodes.push_back(node);
    for (splay_node *node : nodes) {
      *node = splay_node();
      node_pool.push_back(node);
    }
    set_root(nullptr);
  }
  void erase(splay_node *x) {
    splay_node *new_x = nullptr, *fix_node = nullptr;
    if (x->child[0] == nullptr || x->child[1] == nullptr) {
      new_x = x->child[x->child[0] == nullptr ? 1 : 0];
      fix_node = x->parent;
    } else {
      splay_node *next = successor(x);
      assert(next != nullptr && next->child[0] == nullptr);
      new_x = next;
      fix_node = next->parent == x ? next : next->parent;
      next->parent->set_child(next->parent_index(), next->child[1]);
      next->set_child(0, x->child[0]);
      next->set_child(1, x->child[1]);
    }
    if (x == root)
      set_root(new_x);
    else
      x->parent->set_child(x->parent_index(), new_x);
    int depth = 0;
    for (splay_node *node = fix_node; node != nullptr; node = node->parent) {
      node->join();
      depth++;
    }
    if (fix_node != nullptr) check_splay(fix_node, depth);
    *x = splay_node();
    node_pool.push_back(x);
  }
  pair<splay_node *, int> lower_bound(const splay_key &key) {
    splay_node *current = root, *prev = nullptr, *answer = nullptr;
    int below = 0, depth = 0;
    while (current != nullptr) {
      prev = current;
      depth++;
      if (current->key < key) {
        below += splay_node::get_size(current->child[0]) + 1;
        current = current->child[1];
      } else {
        answer = current;
        current = current->child[0];
      }
    }
    if (prev != nullptr) check_splay(prev, depth);
    return make_pair(answer, below);
  }
  bool contains(const splay_key &key) {
    splay_node *node = lower_bound(key).first;
    return node != nullptr && node->key == key;
  }
  bool erase(const splay_key &key) {
    splay_node *x = lower_bound(key).first;
    if (x == nullptr || x->key != key) return false;
    erase(x);
    return true;
  }
  splay_node *node_at_index(int index) {
    if (index < 0 || index >= size()) return nullptr;
    splay_node *current = root;
    int depth = 0;
    while (current != nullptr) {
      int left_size = splay_node::get_size(current->child[0]);
      depth++;
      if (index == left_size) {
        check_splay(current, depth);
        return current;
      }
      if (index < left_size) {
        current = current->child[0];
      } else {
        current = current->child[1];
        index -= left_size + 1;
      }
    }
    assert(false);
  }
  splay_node *query_prefix_key(const splay_key &key) {
    splay_node *node = lower_bound(key).first;
    if (node == nullptr) return root;
    splay(node);
    return node->child[0];
  }
  splay_node *query_prefix_count(int count) {
    if (count <= 0) return nullptr;
    if (count >= size()) return root;
    splay_node *node = node_at_index(count);
    splay(node);
    return node->child[0];
  }
  splay_node *query_suffix_key(const splay_key &key) {
    splay_node *node = lower_bound(key).first;
    if (node == nullptr) return nullptr;
    node = predecessor(node);
    if (node == nullptr) return root;
    splay(node);
    return node->child[1];
  }
  splay_node *query_suffix_count(int count) {
    if (count >= size()) return root;
    if (count <= 0) return nullptr;
    int index = size() - count;
    splay_node *node = node_at_index(index - 1);
    splay(node);
    return node->child[1];
  }
};
bool splay_tree::_exit_delete_setup = false;
vector<splay_node *> splay_tree::node_pool;
vector<splay_node *> splay_tree::pointers_to_delete;
const int INF = 1e9 + 5;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout << fixed << setprecision(8);
  int N, Q;
  cin >> N >> Q;
  splay_tree tree;
  vector<int> A(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i];
    tree.insert(A[i]);
  }
  for (int q = 0; q < Q; q++) {
    int type;
    cin >> type;
    if (type == 1) {
      int p, x;
      cin >> p >> x;
      p--;
      tree.erase(A[p]);
      A[p] = x;
      tree.insert(A[p]);
      continue;
    }
    int64_t v;
    cin >> v;
    auto test = [&](double ans) {
      int64_t xx = int64_t(ceil(ans));
      int x = xx > INF ? INF : int(xx);
      splay_node *node = tree.query_prefix_key(x);
      int count = splay_node::get_size(node);
      int64_t sum = splay_node::get_sum(node);
      return ans * count - sum >= v;
    };
    double low = 0, high = 1e16;
    if (test(1))
      high = 1;
    else
      low = 1;
    for (int iter = 0; iter < 60; iter++) {
      double mid = high <= 1 ? (low + high) / 2 : sqrt(low * high);
      if (test(mid))
        high = mid;
      else
        low = mid;
    }
    cout << low << '\n';
  }
}
