#include "bits/stdc++.h"
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define trav(a, x) for(auto& a : x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vpi;
template <class T>
void rd(T &x) {
int sgn = 1;
char ch;
x = 0;
for (ch = getchar(); (ch < '0' || ch > '9') && ch != '-'; ch = getchar()) ;
if (ch == '-') ch = getchar(), sgn = -1;
for (; '0' <= ch && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
x *= sgn;
}
template <class T>
void wr(T x) {
if (x < 0) putchar('-'), wr(-x);
else if (x < 10) putchar(x + '0');
else wr(x / 10), putchar(x % 10 + '0');
}
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
void usaco(string s){
freopen((s+".in").c_str(), "r", stdin);
freopen((s+".out").c_str(), "w", stdout);
}
pii node[100010];
vector<pii> edge[100010], e[100010];
int n, m, disc[100010], low[100010], tot, stck[100010], tp, color[100010], cnt, w[100010];
bool proc[100010];
char ans[100010];
void tarjan(int x, int id){
disc[x] = low[x] = ++tot;
stck[++tp] = x;
proc[x] = 1;
for(auto p: edge[x]){
int y = p.first;
if(p.second == id)
continue;
if(!disc[y]){
tarjan(y, p.second);
low[x] = min(low[x], low[y]);
}
else if(proc[y])
low[x] = min(low[x], disc[y]);
}
if(disc[x] == low[x]){
int y;
++cnt;
do{
y = stck[tp--];
proc[y] = 0;
color[y] = cnt;
}while(y != x);
}
}
void dfs(int x, int fa){
disc[x] = -1;
for(auto p: e[x]){
int y = p.first, id = p.second;
if(y == fa)
continue;
dfs(y, x);
w[x] += w[y];
if(!w[y])
ans[id] = 'B';
else if(w[y] > 0)
ans[id] = (node[id] == pii(y, x)) ? 'R' : 'L';
else
ans[id] = (node[id] == pii(x, y)) ? 'R' : 'L';
}
}
int main() {
#ifdef LOCAL_DEFINE
freopen("input.txt", "r", stdin);
#endif
cin >> n >> m;
int x, y;
for(int i = 1; i <= m; i++){
cin >> x >> y;
node[i] = pii(x, y);
edge[x].push_back(pii(y, i));
edge[y].push_back(pii(x, i));
}
for(int i = 1; i <= n; i++)
if (!disc[i])
tarjan(i, 0);
for (int i = 1; i <= m; i++){
if (color[node[i].first] == color[node[i].second]){
ans[i] = 'B';
continue;
}
x = color[node[i].first], y = color[node[i].second];
e[x].push_back(pii(y, i));
e[y].push_back(pii(x, i));
node[i] = pii(x, y);
}
int qq;
cin >> qq;
while(qq--){
cin >> x >> y;
if(color[x] == color[y]) continue;
x = color[x], y = color[y];
w[x]++, w[y]--;
}
for(int i = 1; i <= n; i++)
if(disc[i] >= 0)
dfs(i, 0);
for(int i = 1; i <= m; i++) cout << ans[i];
}
