diff --git a/trees/multitreap.hh b/trees/multitreap.hh
deleted file mode 100644
index 4c5be5b..0000000
--- a/trees/multitreap.hh
+++ /dev/null
@@ -1,147 +0,0 @@
-// @link https://www.acwing.com/file_system/file/content/whole/index/content/8807719/
-// Index starts from 1
-
-template <typename T> class multitreap {
-
-#define lson fhq[u].l
-#define rson fhq[u].r
-
-private:
-    using size_type = size_t;
-    using value_type = T;
-    using reference = value_type&;
-    using const_reference = const reference;
-    using element_type = pair<value_type, size_type>;
-
-    struct Node {
-        int key;
-        size_type l, r, size;
-        element_type val;
-    };
-    vector<Node> fhq;
-    size_type cnt, root;
-    size_type x, y, z;
-    size_type _size;
-
-    void pushup(size_type u) {
-        fhq[u].size = fhq[lson].size + fhq[rson].size + 1;
-    }
-
-    size_type node(value_type val) {
-        if (cnt + 1 >= fhq.size()) {
-            fhq.push_back({});
-        }
-        fhq[++cnt].val = {val, cnt};
-        fhq[cnt].key = rand();
-        fhq[cnt].size = 1;
-        return cnt;
-    }
-
-    void split(size_type u, value_type val, size_type &x, size_type &y) {
-        if (!u) x = y = 0;
-        else {
-            if (!greater<element_type>()(fhq[u].val, {val, cnt})) x = u, split(rson, val, rson, y);
-            else y = u, split(lson, val, x, lson);
-            pushup(u);
-        }
-    }
-
-    size_type merge(size_type x, size_type y) {
-        if (!x || !y) return x + y;
-        if (fhq[x].key <= fhq[y].key) {
-            fhq[x].r = merge(fhq[x].r, y);
-            pushup(x);
-            return x;
-        } else {
-            fhq[y].l = merge(x, fhq[y].l);
-            pushup(y);
-            return y;
-        }
-    }
-
-    value_type askNum(size_type u, size_type rank) {
-        if (fhq[lson].size + 1 == rank) return fhq[u].val.first;
-        if (fhq[lson].size >= rank) return askNum(lson, rank);
-        else return askNum(rson, rank - fhq[lson].size - 1);
-    }
-
-public:
-    multitreap() : fhq(1), cnt(0), root(0), _size(0) {}
-    explicit multitreap(size_type n) : fhq(1), cnt(0), root(0), _size(0) {
-        fhq.reserve(n + 1);
-    }
-
-    template<typename _InputIterator,
-             typename = std::_RequireInputIter<_InputIterator>>
-        multitreap(_InputIterator __first, _InputIterator __last)
-        : fhq(1), cnt(0), root(0), _size(0) {
-            __try {
-                for (; __first != __last; ++__first) {
-                    insert(*__first);
-                }
-            } __catch(...) {
-                clear();
-                __throw_exception_again;
-            }
-    }
-
-    void clear() {
-        _size = root = cnt = 0;
-        fill(fhq.begin(), fhq.end(), {});
-    }
-
-    void insert(value_type val) {
-        ++_size;
-        split(root, val, x, y);
-        root = merge(merge(x, node(val)), y);
-    }
-
-    void remove(value_type val) {
-        assert(contains(val));
-        --_size;
-        split(root, val, x, z);
-        split(x, val - 1, x, y);
-        y = merge(fhq[y].l, fhq[y].r);
-        root = merge(merge(x, y), z);
-    }
-
-    size_type index_of(value_type val) {
-        split(root, val - 1, x, y);
-        size_type res = fhq[x].size + 1;
-        root = merge(x, y);
-        return res;
-    }
-
-    value_type at(size_type rank) {
-        assert(rank > 0 && rank <= _size);
-        return askNum(root, rank);
-    }
-
-    value_type prev_element(value_type val) {
-        split(root, val - 1, x, y);
-        size_type u = x;
-        while (rson) u = rson;
-        root = merge(x, y);
-        return fhq[u].val.first;
-    }
-
-    value_type next_element(value_type val) {
-        split(root, val, x, y);
-        size_type u = y;
-        while (lson) u = lson;
-        root = merge(x, y);
-        return fhq[u].val.first;
-    }
-
-    bool contains(value_type val) {
-        size_type idx = index_of(val);
-        return idx <= _size && at(idx) == val;
-    }
-
-    size_type size() {
-        return _size;
-    }
-
-#undef lson
-#undef rson
-};