#include "gift.h"
#include <bits/stdc++.h>
using namespace std;
int construct(int n, int r, std::vector<int> a, std::vector<int> b, std::vector<int> x) {
vector <pair <int, int>> ee, ff;
for (int i = 0; i < r; i++) {
if (x[i] == 1) {
ee.push_back({a[i], b[i]});
} else {
ff.push_back({a[i], b[i]});
}
}
for (int i = 0; i < n; i++) {
ee.push_back({i, i});
}
{
sort(ee.begin(), ee.end());
auto g = ee; ee.clear();
for (auto i : g) {
if (ee.empty() || ee.back().second < i.first) {
ee.push_back(i);
}
ee.back().second = max(ee.back().second, i.second);
}
}
string s;
for (int i = 0; i < n; i++) {
s += 'R';
}
int v = 0;
for (int i = 1; i < (int)ee.size(); i++) {
if (ee[i].first == ee[i - 1].second + 1) {
v ^= 1;
} else {
for (int j = ee[i - 1].second + 1; j < ee[i].first; j++) {
s[j] = (v == 1 ? 'R' : 'B');
}
}
for (int j = ee[i].first; j <= ee[i].second; j++) {
s[j] = (v == 0 ? 'R' : 'B');
}
}
for (auto [x, y] : ff) {
auto g = lower_bound(ee.begin(), ee.end(), pair <int, int> {x + 1, 0}) - ee.begin();
if (g != 0) {
g--;
if (ee[g].first <= x && y <= ee[g].second) {
return 0;
}
}
}
craft(s); return 1;
}
