#include "gift.h"
#include <bits/stdc++.h>
using namespace std;
int construct(int n, int R, vector<int> a, vector<int> b, vector<int> x) {
string s="";
vector<int> sl(n+1, 0);
for (int i=0; i<R; i++) {
int l=a[i], r=b[i];
if (x[i] == 1) {
sl[l]++;
sl[r+1]--;
}
}
for (int i=1; i<=n; i++) sl[i] += sl[i-1];
for (int i=0; i<=n; i++) if (sl[i] > 1) sl[i] = 1;
vector<int> prf(n, 0);
prf[0] = sl[0];
for (int i=1; i<n; i++) prf[i] = prf[i-1] + sl[i];
for (int i=0; i<R; i++) {
int l=a[i], r=b[i];
if (x[i] == 2) {
if (prf[r] - (l-1 >=0 ? prf[l-1] : 0) >= r-l+1) return 0;
}
}
char cur='R';
for (int i=0; i<n; i++) {
if (sl[i] == 0 || sl[i] != sl[i-1]) {
if (cur == 'R') cur = 'B';
else cur = 'R';
}
s+=cur;
}
craft(s);
return 1;
}
