#include <bits/stdc++.h>
using namespace std;
int a, b;
vector<pair<int,int>> z[100005];
pair<int,int> edge[100005];
int id[100005], low[100005];
int cnt = 0;
int check[100005];
bool vis[100005];
int ver = 0;
int par[100005], sz[100005];
int mark[100005];
struct node {
int x, id, flip;
};
vector<node> z1[100005];
pair<int,int> rev[100005];
int ans[100005];
int high[100005];
int up[100005][25];
int xuoi[100005], ngc[100005];
int sta[100005], fin[100005], tour = 0;
unordered_map<long long,int> m;
long long hash_pair(int x, int y) {
return 1LL * x * 1000000 + y;
}
void dfs(int i, int parent) {
cnt++;
id[i] = low[i] = cnt;
for (auto p : z[i]) {
int nxt = p.first, eId = p.second;
if(nxt == parent) continue;
if(id[nxt])
low[i] = min(low[i], id[nxt]);
else {
dfs(nxt, i);
low[i] = min(low[i], low[nxt]);
if(low[nxt] >= id[i])
check[eId] = 1;
}
}
}
int find(int u) {
return (par[u] == u ? u : par[u] = find(par[u]));
}
void join(int x, int y) {
x = find(x);
y = find(y);
if(x == y) return;
if(sz[x] < sz[y]) swap(x, y);
sz[x] += sz[y];
par[y] = x;
}
void predfs(int i, int parent) {
tour++;
sta[i] = tour;
up[i][0] = parent;
for (auto p : z1[i]) {
if(p.x == parent) continue;
high[p.x] = high[i] + 1;
rev[p.x] = {p.id, p.flip};
predfs(p.x, i);
}
fin[i] = tour;
}
int lca(int x, int y) {
if(high[x] < high[y]) swap(x, y);
for (int i = 20; i >= 0; i--) {
if(high[ up[x][i] ] >= high[y])
x = up[x][i];
}
if (x==y) return x;
for (int i = 20; i >= 0; i--) {
if(up[x][i] != up[y][i] && up[x][i] != 0) {
x = up[x][i];
y = up[y][i];
}
}
return up[x][0];
}
void dfs1(int i, int parent) {
for (auto p : z1[i]) {
if(p.x == parent) continue;
dfs1(p.x, i);
xuoi[i] += xuoi[p.x];
ngc[i] += ngc[p.x];
if (xuoi[p.x] > 0 && m[hash_pair(i, p.x)] <= 1)
ans[rev[p.x].first] = 1 * rev[p.x].second;
if (ngc[p.x] > 0 && m[hash_pair(i, p.x)] <= 1)
ans[rev[p.x].first] = -1 * rev[p.x].second;
}
}
signed main(){
if (fopen("oneway.inp","r")){
freopen("oneway.inp","r",stdin);
freopen("oneway.out","w",stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> a >> b;
for (int i = 1; i <= b; i++){
int x, y;
cin >> x >> y;
z[x].push_back({y, i});
z[y].push_back({x, i});
edge[i] = {x, y};
}
for (int i = 1; i <= a; i++){
if(!id[i])
dfs(i, 0);
}
for (int i = 1; i <= a; i++){
par[i] = i;
sz[i] = 1;
}
for (int i = 1; i <= b; i++){
if(!check[i])
join(edge[i].first, edge[i].second);
}
for (int i = 1; i <= a; i++){
int x = find(i);
if(!vis[x]){
vis[x] = true;
ver++;
mark[x] = ver;
}
mark[i] = mark[x];
}
for (int i = 1; i <= b; i++){
int x = mark[ edge[i].first ];
int y = mark[ edge[i].second ];
if(x == y) continue;
z1[x].push_back({y, i, 1});
z1[y].push_back({x, i, -1});
m[hash_pair(x,y)]++;
m[hash_pair(y,x)]++;
}
high[0] = -1;
for (int i = 1; i <= ver; i++){
if(sta[i] == 0){
high[i] = 0;
predfs(i, 0);
}
}
for (int j = 1; j <= 20; j++){
for (int i = 1; i <= ver; i++){
int parNode = up[i][j-1];
if(parNode == 0)
up[i][j] = 0;
else
up[i][j] = up[ parNode ][j-1];
}
}
int q;
cin >> q;
for (int i = 1; i <= q; i++){
int x, y;
cin >> x >> y;
x = mark[x];
y = mark[y];
if (x==y) continue;
int l = lca(x, y);
xuoi[x]++;
xuoi[l]--;
ngc[y]++;
ngc[l]--;
}
for (int i = 1; i <= ver; i++){
if(up[i][0] == 0) {
dfs1(i, 0);
}
}
for (int i = 1; i <= b; i++){
if(ans[i] == 0)
cout << "B";
else if(ans[i] < 0)
cout << "R";
else
cout << "L";
}
return 0;
}
