// Calm down.
// Think three times, code twice.
#include "bits/stdc++.h"
#define forr(_a,_b,_c) for(int _a = (_b); _a <= (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < (_c); ++_a)
#define st first
#define nd second
#define ll long long
#define ull unsigned long long
#define pii pair <int,int>
#define pll pair <ll,ll>
#define piii pair <int,pii>
#define vi vector <int>
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"
using namespace std;
const int N = 2e5 + 5;
const int mod = 1e9 + 7; // 998244353
const ll oo = 1e18;
int n, m, p, low[N], num[N], par[N], color[N], timer = 0, scc = 0, h[N], p2[N], tin[N], head[N], heavy[N], res[N], euler[N];
stack<int> s;
bool deleted[N];
vector<pii> a[N], g[N];
char ans[N];
pii f[N], tmp[N];
void dfs(int u, int pre) {
num[u] = low[u] = ++timer;
s.push(u);
for(pii e: a[u]) {
int v = e.st, cur = e.nd;
if(deleted[v] || cur == pre) continue;
if(!num[v]) {
par[v] = u;
dfs(v, cur);
low[u] = min(low[u], low[v]);
} else low[u] = min(low[u], num[v]);
}
// cout << u << " " << num[u] << " " << low[u] << "\n";
if(low[u] == num[u]) {
scc++;
int v;
do {
v = s.top();
s.pop();
deleted[v] = 1;
color[v] = scc;
} while(v != u);
}
}
int dfs2(int u, int pre) {
int sz = 0, mx = 0;
for(pii e: g[u]) {
int v = e.st;
if(v == pre) continue;
h[v] = h[u] + 1;
p2[v] = u;
int cur = dfs2(v, u);
if(cur > mx) {
mx = cur;
heavy[u] = v;
}
sz += cur;
}
return sz;
}
void hld(int u, int cur) {
tin[u] = ++timer;
euler[timer] = u;
head[u] = cur;
if(heavy[u]) {
hld(heavy[u], cur);
}
for(pii e: g[u]) {
int v = e.st;
if(v == p2[u] || v == heavy[u]) continue;
hld(v, v);
}
}
struct seg {
vector<int> t, lazy;
int n;
void init(int _n) {
n = _n;
t.assign(4 * n + 5, 0);
lazy.assign(4 * n + 5, 0);
}
void push_down(int id, int l, int r, int mid) {
if(!lazy[id]) return;
int val = lazy[id]; lazy[id] = 0;
t[id << 1] = t[id << 1 | 1] = lazy[id << 1] = lazy[id << 1 | 1] = val;
}
void update(int id, int l, int r, int u, int v, int val) {
if(l > v || r < u || l > r || u > v) return;
if(u <= l && r <= v) {
t[id] = val;
lazy[id] = val;
return;
}
int mid = (l + r) >> 1;
push_down(id, l, r, mid);
update(id << 1, l, mid, u, v, val);
update(id << 1 | 1, mid + 1, r, u, v, val);
t[id] = max(t[id << 1], t[id << 1 | 1]);
}
void down(int id, int l, int r) {
if(l == r) {
// cout << l << " " << t[id] << "\n";
res[euler[l]] = t[id];
return;
}
int mid = (l + r) >> 1;
push_down(id, l, r, mid);
down(id << 1, l, mid);
down(id << 1 | 1, mid + 1, r);
}
void update(int u, int v, int val) {
update(1, 1, n, u, v, val);
}
} it;
void update(int u, int v) {
while(head[u] != head[v]) {
if(tin[head[u]] < tin[head[v]]) {
it.update(tin[head[v]], tin[v], 2);
v = p2[head[v]];
} else {
it.update(tin[head[u]], tin[u], 1);
u = p2[head[u]];
}
}
if(tin[u] < tin[v]) {
it.update(tin[u] + 1, tin[v], 2);
} else {
it.update(tin[v] + 1, tin[u], 1);
}
}
void dfs3(int u, int pre) {
for(pii e: g[u]) {
int v = e.st, id = e.nd;
if(v == pre) continue;
dfs3(v, u);
// cout << u << " " << v << " " << res[v] << "\n";
if(res[v] == 1) {
int l = v, r = u;
if(l == tmp[id].st && r == tmp[id].nd) {
ans[id] = 'R';
} else {
ans[id] = 'L';
}
} else if(res[v] == 2) {
int l = u, r = v;
if(l == tmp[id].st && r == tmp[id].nd) {
ans[id] = 'R';
} else {
ans[id] = 'L';
}
} else {
ans[id] = 'B';
}
}
}
void to_nho_cau() {
cin >> n >> m;
forr(i, 1, m) {
int u, v; cin >> u >> v;
a[u].pb({v, i});
a[v].pb({u, i});
f[i].st = u; f[i].nd = v;
}
dfs(1, 0);
// forr(i, 1, n) cout << color[i] << " ";
forr(i, 1, m) {
int u = color[f[i].st], v = color[f[i].nd];
if(u != v) {
g[u].pb({v, i});
g[v].pb({u, i});
tmp[i] = {u, v};
// cout << u << " " << v << "\n";
} else {
// cout << i << "\n";
ans[i] = 'B';
}
}
timer = 0;
dfs2(1, 0);
hld(1, 1);
it.init(timer);
cin >> p;
forr(i, 1, p) {
int u, v; cin >> u >> v;
u = color[u], v = color[v];
// cout << u << " " << v << "\n";
update(u, v);
}
it.down(1, 1, timer);
// forr(i, 1, n) cout << res[i] << " "; cout << "\n";
dfs3(1, 0);
forr(i, 1, m) cout << ans[i];
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);
#ifdef LOCAL
freopen(file".inp","r",stdin);
freopen(file".out","w",stdout);
#endif
int t = 1;
//cin >> t;
while(t--) to_nho_cau();
}
/*
1.self check:
2.long long
3.size of array
4.code for testing
5.initializing
6.modulo number
*/
/**
∧__∧
（｀•ω• )づ__∧
（つ /( •ω•。)
しーＪ (nnノ) pat pat
**/
/** /\_/\
* (= ._.)
* / >☕ \>💻
**/
