#include <bits/stdc++.h>
#include "grader.h"
#pragma GCC optimize("O3, unroll-loops")
using namespace std;
using ll = long long;
int char_to_index(char x) {
if (x == 'A') return 0;
if (x == 'C') return 1;
if (x == 'G') return 2;
if (x == 'T') return 3;
throw 1;
}
struct Node {
Node *l, *r;
int cnt[4], prior, siz;
char c;
Node(char x) {
c = x;
fill(cnt, cnt+4, 0);
cnt[char_to_index(x)]++;
prior = rand();
siz = 1;
l = r = nullptr;
}
};
int get_size(Node *ptr) {
return ptr ? ptr->siz : 0;
}
void pull(Node *v) {
v->siz = 1 + get_size(v->l) + get_size(v->r);
fill(v->cnt, v->cnt+4, 0);
v->cnt[char_to_index(v->c)] = 1;
if (v->l) {
for (int i = 0; i < 4; i++) {
v->cnt[i] += v->l->cnt[i];
}
}
if (v->r) {
for (int i = 0; i < 4; i++) {
v->cnt[i] += v->r->cnt[i];
}
}
}
Node *merge(Node *l, Node *r) {
if (!l || !r) return l ? l : r;
if (l->prior > r->prior) {
l->r = merge(l->r, r);
pull(l);
return l;
} else {
r->l = merge(l, r->l);
pull(r);
return r;
}
}
pair<Node *, Node *> split(Node *v, int x) {
if (!v) return {nullptr, nullptr};
if (get_size(v->l) < x) {
auto [l, r] = split(v->r, x - 1 - get_size(v->l));
v->r = l;
pull(v);
return {v, r};
} else {
auto [l, r] = split(v->l, x);
v->l = r;
pull(v);
return {l, v};
}
}
void print(Node *v, string &res) {
if (v->l) print(v->l, res);
res += v->c;
if (v->r) print(v->r, res);
}
Node *root = nullptr;
void Kezd(string s) {
srand(2);
for (char c : s) {
root = merge(root, new Node(c));
}
}
void Beszur(int i, char x) {
auto [a, b] = split(root, i);
root = merge(a, merge(new Node(x), b));
}
void Mutal(int i, char x) {
auto [a, b] = split(root, i-1);
auto [c, d] = split(b, 1);
root = merge(a, merge(new Node(x), d));
}
void Kivag(int i, int j) {
auto [a, b] = split(root, i-1);
auto [c, d] = split(b, j-i+1);
root = merge(a, d);
}
int Szamlal(int i, int j, char x) {
auto [a, b] = split(root, i-1);
auto [c, d] = split(b, j-i+1);
int res = c->cnt[char_to_index(x)];
root = merge(a, merge(c, d));
return res;
}
string Eredmeny() {
string res;
if (root) print(root, res);
return res;
}
/*
int main() {
string s; cin >> s;
Kezd(s);
while (true) {
int op; cin >> op;
cerr << op << endl;
if (op == 0) {
break;
}
if (op == 1) {
int x; char c; cin >> x >> c;
Beszur(x, c);
}
if (op == 2) {
int x; char c; cin >> x >> c;
Mutal(x, c);
}
if (op == 3) {
int l, r; cin >> l >> r;
Kivag(l, r);
}
if (op == 4) {
int l, r, ans; char c; cin >> l >> r >> c >> ans;
int res = Szamlal(l, r, c);
// if (ans == res) cout << "Correct\n";
// else cout << "Incorrect: " << ans << " " << res << "\n";
}
if (op == 5) {
string res = Eredmeny();
string ans; cin >> ans;
ans.pop_back();
// if (ans == res) cout << "Correct\n";
// else cout << "Incorrect: " << ans << " " << res << "\n";
}
cout << Eredmeny() << "\n";
}
}
*/