Letters Removing

Petya has a string of length n consisting of small and large English letters and digits.

He performs m operations. Each operation is described with two integers l and r and a character c: Petya removes from the string all characters c on positions between l and r, inclusive. It’s obvious that the length of the string remains the same or decreases after each operation.

Find how the string will look like after Petya performs all m operations.

Input

The first string contains two integers n and m (1 ≤ n, m ≤ 2·10⁵) — the length of the string and the number of operations.

The second line contains the string of length n, consisting of small and large English letters and digits. Positions in the string are enumerated from 1.

Each of the next m lines contains two integers l and r (1 ≤ l ≤ r), followed by a character c, which is a small or large English letter or a digit. This line describes one operation. It is guaranteed that r doesn’t exceed the length of the string s before current operation.

Output

Print the string Petya will obtain after performing all m operations. If the strings becomes empty after all operations, print an empty line.

Examples

input

4 2
abac
1 3 a
2 2 c

output

b

input

3 2
A0z
1 3 0
1 1 z

output

Az

input

10 4
agtFrgF4aF
2 5 g
4 9 F
1 5 4
1 7 a

output

tFrg4

input

9 5
aAAaBBccD
1 4 a
5 6 c
2 3 B
4 4 D
2 3 A

output

AB

Note

In the first example during the first operation both letters ‘a’ are removed, so the string becomes “bc”. During the second operation the letter ‘c’ (on the second position) is removed, and the string becomes “b”.

In the second example during the first operation Petya removes ‘0’ from the second position. After that the string becomes “Az”. During the second operations the string doesn’t change.

Solution:

#include <bits/stdc++.h>

using namespace std;

mt19937 rng((unsigned int) chrono::steady_clock::now().time_since_epoch().count());

class node {
public:
int id;
node* l;
node* r;
node* p;
bool rev;
int sz;
// declare extra variables:
int P;

node(int _id) {
id = _id;
l = r = p = NULL;
rev = false;
sz = 1;
// init extra variables:
P = rng();
}

void unsafe_reverse() {
rev ^= 1;
swap(l, r);
pull();
}

// apply changes:
void unsafe_apply() {

}

void push() {
if (rev) {
if (l != NULL) {
l->unsafe_reverse();
}
if (r != NULL) {
r->unsafe_reverse();
}
rev = 0;
}
// now push everything else:

}

void pull() {
sz = 1;
// now init from self:

if (l != NULL) {
l->p = this;
sz += l->sz;
// now pull from l:

}
if (r != NULL) {
r->p = this;
sz += r->sz;
// now pull from r:

}
}
};

void debug_node(node* v, string pref = "") {
#ifdef LOCAL
if (v != NULL) {
debug_node(v->r, pref + " ");
cerr << pref << "-" << " " << v->id << '\n';
      debug_node(v->l, pref + " ");
} else {
cerr << pref << "-" << " " << "NULL" << '\n';
    }
  #endif
}

namespace treap {
  pair<node*,int> find(node* v, const function<int(node*)> &go_to) {
// go_to returns: 0 -- found; -1 -- go left; 1 -- go right
// find returns the last vertex on the descent and its go_to
if (v == NULL) {
return {NULL, 0};
}
int dir;
while (true) {
v->push();
dir = go_to(v);
if (dir == 0) {
break;
}
node* u = (dir == -1 ? v->l : v->r);
if (u == NULL) {
break;
}
v = u;
}
return {v, dir};
}

node* get_leftmost(node* v) {
return find(v, [&](node*) { return -1; }).first;
}

node* get_rightmost(node* v) {
return find(v, [&](node*) { return 1; }).first;
}

node* get_kth(node* v, int k) { // 0-indexed
pair<node*,int> p = find(v, [&](node* u) {
if (u->l != NULL) {
if (u->l->sz > k) {
return -1;
}
k -= u->l->sz;
}
if (k == 0) {
return 0;
}
k--;
return 1;
});
return (p.second == 0 ? p.first : NULL);
}

int get_position(node* v) { // 0-indexed
int k = (v->l != NULL ? v->l->sz : 0);
while (v->p != NULL) {
if (v == v->p->r) {
k++;
if (v->p->l != NULL) {
k += v->p->l->sz;
}
}
v = v->p;
}
return k;
}

node* get_bst_root(node* v) {
while (v->p != NULL) {
v = v->p;
}
return v;
}

pair<node*,node*> split(node* v, const function<bool(node*)> &is_right) {
if (v == NULL) {
return {NULL, NULL};
}
v->push();
if (is_right(v)) {
pair<node*,node*> p = split(v->l, is_right);
if (p.first != NULL) {
p.first->p = NULL;
}
v->l = p.second;
v->pull();
return {p.first, v};
} else {
pair<node*,node*> p = split(v->r, is_right);
v->r = p.first;
if (p.second != NULL) {
p.second->p = NULL;
}
v->pull();
return {v, p.second};
}
}

pair<node*,node*> split_leftmost_k(node* v, int k) {
return split(v, [&](node* u) {
int left_and_me = (u->l != NULL ? u->l->sz : 0) + 1;
if (k >= left_and_me) {
k -= left_and_me;
return false;
}
return true;
});
}

node* merge(node* v, node* u) {
if (v == NULL) {
return u;
}
if (u == NULL) {
return v;
}
if (v->P > u->P) {
//    if (rng() % (v->sz + u->sz) < (unsigned int) v->sz) {
v->push();
v->r = merge(v->r, u);
v->pull();
return v;
} else {
u->push();
u->l = merge(v, u->l);
u->pull();
return u;
}
}

int count_left(node* v, const function<bool(node*)> &is_right) {
if (v == NULL) {
return 0;
}
v->push();
if (is_right(v)) {
return count_left(v->l, is_right);
}
return (v->l != NULL ? v->l->sz : 0) + 1 + count_left(v->r, is_right);
}

node* add(node* r, node* v, const function<bool(node*)> &go_left) {
pair<node*,node*> p = split(r, go_left);
return merge(p.first, merge(v, p.second));
}

node* remove(node* v) { // returns the new root
v->push();
node* x = v->l;
node* y = v->r;
node* p = v->p;
v->l = v->r = v->p = NULL;
v->push();
v->pull(); // now v might be reusable...
node* z = merge(x, y);
if (p == NULL) {
if (z != NULL) {
z->p = NULL;
}
return z;
}
if (p->l == v) {
p->l = z;
}
if (p->r == v) {
p->r = z;
}
while (true) {
p->push();
p->pull();
if (p->p == NULL) {
break;
}
p = p->p;
}
return p;
}

node* next(node* v) {
if (v->r == NULL) {
while (v->p != NULL && v->p->r == v) {
v = v->p;
}
return v->p;
}
v->push();
v = v->r;
while (v->l != NULL) {
v->push();
v = v->l;
}
return v;
}

node* prev(node* v) {
if (v->l == NULL) {
while (v->p != NULL && v->p->l == v) {
v = v->p;
}
return v->p;
}
v->push();
v = v->l;
while (v->r != NULL) {
v->push();
v = v->r;
}
return v;
}

int get_size(node* v) {
return (v != NULL ? v->sz : 0);
}

template<typename... T>
void apply(node* v, T... args) {
v->unsafe_apply(args...);
}

void reverse(node* v) {
v->unsafe_reverse();
}
}

using namespace treap;

int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, m;
cin >> n >> m;
string s;
cin >> s;
map<char,set<int>> mp;
for (int i = 0; i < n; i++) {
    mp[s[i]].insert(i);
  }
  node* v = NULL;
  vector<node*> nodes(n);
for (int i = 0; i < n; i++) {
    nodes[i] = new node(i);
    v = merge(v, nodes[i]);
  }
  while (m--) {
    int l, r;
    char c;
    cin >> l >> r >> c;
l--; r--;
l = get_kth(v, l)->id;
r = get_kth(v, r)->id;
while (true) {
auto it = mp.lower_bound(l);
if (it == mp.end() || *it > r) {
break;
}
v = remove(nodes[*it]);
mp.erase(it);
}
}
v = get_leftmost(v);
while (v != NULL) {
cout << s[v->id];
v = next(v);
}
cout << '\n';
  return 0;
}