#include "gift.h"
#include<bits/stdc++.h>
using namespace std;
const int nx = 5e5+5;
int add[nx], sub[nx], last[nx]; // R, B
vector<pair<int,int>> t2;
int construct(int n, int r, std::vector<int> a, std::vector<int> b, std::vector<int> x)
{
string res = "";
for(int i = 0; i < r; i++)
{
if(x[i] == 1)
{
add[a[i]]++;
sub[b[i]]++;
}
else t2.push_back({a[i],b[i]});
}
string cur = "R";
int sum = 0;
for(int i = 0; i < n; i++)
{
sum += add[i];
res += cur;
if(sum > 0) cur = cur;
else if(cur == "R") cur = "B";
else cur = "R";
sum -= sub[i];
}
for(int i = 1; i < n; i++)
{
last[i] = last[i-1];
if(res[i]!=res[i-1]) last[i] = i-1;
}
for(auto [l,r] : t2)
{
if(last[r] >= l) continue;
else return 0;
}
craft(res);
return 1;
}
