#include <bits/stdc++.h>
#include "gift.h"
#include <vector>
#include <cassert>
#include <cstdio>
#include <string>
using namespace std;
int smen[500005];
int ok[500005];
int construct(int n, int r, std::vector<int> a, std::vector<int> b, std::vector<int> x) {
int i;
for (i=0;i<r;i++)
{
a[i]++;b[i]++;
if (a[i]==b[i]&&x[i]==2)
{
return 0;
}
}
for (i=0;i<=n;i++)
{
smen[i]=ok[i]=0;
}
for (i=0;i<r;i++)
{
if (x[i]==1)
{
smen[a[i]]++;
smen[b[i]+1]--;
}
}
for (i=1;i<=n;i++)
{
smen[i]=smen[i]+smen[i-1];
if (smen[i]!=0)
{
ok[i]=ok[i-1]+1;
}
}
for (i=0;i<r;i++)
{
if (x[i]==1)
{
continue;
}
if (ok[b[i]]-ok[a[i]-1]==b[i]-a[i]+1)
{
return 0;
}
}
string s;
s.resize(n);
s[0]='R';
for (i=1;i<n;i++)
{
if (ok[i+1]<=1)
{
if (s[i-1]=='R')
{
s[i]='B';
}
else
{
s[i]='R';
}
}
else
{
s[i]=s[i-1];
}
}
craft(s);
return 1;
}
#ifdef HOME
static int n, r;
static std::vector<int> a, b, x;
static std::string s;
static int possible = 0;
static int called = 0;
void craft(std::string &_s)
{
assert(!called);
s = _s;
assert((int) s.size() == n);
for (int i = 0; i < n; i++) {
assert(s[i] == 'R' || s[i] == 'B');
}
called = 1;
}
int main()
{
assert(scanf("%d %d", &n, &r) == 2);
a.resize(r);
b.resize(r);
x.resize(r);
for (int i = 0; i < r; i++) {
assert(scanf("%d %d %d", &a[i], &b[i], &x[i]) == 3);
}
fclose(stdin);
possible = construct(n, r, a, b, x);
assert(possible == 0 || possible == 1);
printf("%d\n", possible);
if (possible == 1) {
printf("%s\n", s.c_str());
} else {
assert(!called);
}
}
#endif // HOME
