#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i = a; i <= b; i++)
#define FOD(i,a,b) for(int i = a; i >= b; i--)
//#define int long long
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ull unsigned long long
#define db double
#define lcm(a,b) a / __gcd(a, b) * b
#define ii pair<int,int>
#define iii pair<int,pair<int,int>>
#define iv pair<pair<int,int>,pair<int,int>>
#define sq(a) (a) * (a)
#define MASK(i) (1LL << i)
#define task "task"
const int inf = 1e9;
const ll INF = 1e18;
const int mod = 1e9 + 7;
const int N = 1e5 + 2;
int n, m, q;
vector<ii> g[N];
ii ed[N];
int ans[N];
int times, scc;
int low[N], num[N], used[N], del[N];
stack<int> st;
vector<iii> ng[N];
ii idx[N];
int par[18][N], vis[N], dp1[N], dp2[N], h[N];
void dfs(int u) {
st.push(u);
low[u] = num[u] = ++times;
for(auto H : g[u]) {
int v = H.fi;
int id = H.se;
if(used[id] || del[v]) continue;
used[id] = 1;
if(!num[v]) {
dfs(v);
low[u] = min(low[u], low[v]);
}
else low[u] = min(low[u], num[v]);
}
if(low[u] == num[u]) {
int v;
scc++;
do {
v = st.top();
st.pop();
del[v] = scc;
}
while(u != v);
}
}
void dfs2(int u, int p) {
par[0][u] = p;
for(auto H : ng[u]) {
int v = H.fi;
if(v == p) continue;
h[v] = h[u] + 1;
idx[v] = H.se;
dfs2(v, u);
}
}
int lca(int u, int v) {
if(h[u] < h[v]) swap(u, v);
int dif = h[u] - h[v];
FOD(i, 17, 0) if((dif >> i) & 1) u = par[i][u];
if(u == v) return u;
FOD(i, 17, 0) {
if(par[i][u] != par[i][v]) {
u = par[i][u];
v = par[i][v];
}
}
return par[0][u];
}
void dfs3(int u, int p) {
vis[u] = 1;
for(auto H : ng[u]) {
int v = H.fi;
if(v == p) continue;
dfs3(v, u);
dp1[u] += dp1[v];
dp2[u] += dp2[v];
}
}
void Solve() {
FOR(i, 1, n) if(!num[i]) dfs(i);
FOR(i, 1, m) {
int u = del[ed[i].fi];
int v = del[ed[i].se];
if(u != v) {
ng[u].pb({v, {i, 0}});
ng[v].pb({u, {i, 1}});
}
}
FOR(i, 1, scc) if(par[0][i] == 0) dfs2(i, -1);
FOR(i, 1, 17) FOR(j, 1, n) par[i][j] = par[i - 1][par[i - 1][j]];
cin >> q;
FOR(i, 1, q) {
int u, v;
cin >> u >> v;
u = del[u];
v = del[v];
if(u == v) continue;
int p = lca(u, v);
dp1[u]++;
dp2[v]++;
dp1[p]--;
dp2[p]--;
}
FOR(i, 1, scc) if(!vis[i]) dfs3(i, -1);
FOR(i, 1, scc) {
if(dp1[i]) {
if(idx[i].se == 0) ans[idx[i].fi] = 2;
else ans[idx[i].fi] = 1;
}
else if(dp2[i]) {
if(idx[i].se) ans[idx[i].fi] = 2;
else ans[idx[i].fi] = 1;
}
}
FOR(i, 1, m) {
if(ans[i] == 0) cout << 'B';
else if(ans[i] == 1) cout << 'R';
else cout << 'L';
}
}
signed main() {
if(fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int test = 1;
// cin >> test;
while(test--) {
cin >> n >> m;
FOR(i, 1, m) {
int u, v;
cin >> u >> v;
g[u].pb({v, i});
g[v].pb({u, i});
ed[i] = {u, v};
}
Solve();
}
}
