//Power Of Ninja Go
#include <bits/stdc++.h>
//#ifdef atom #else #endif
using namespace std;
typedef long long ll; typedef pair<int, int> ii;
#define X first
#define Y second
#define vi vector<int>
#define vii vector< ii >
#define pb push_back
const int maxn = 1e5+5;
vii adj[maxn];
vii tree[maxn];
ii e[maxn];
bool isB[maxn];
int num[maxn];
int low[maxn];
int bcc[maxn];
int dp[22][maxn];
int ans[maxn];
int link[maxn];
int sw[maxn];
int dep[maxn];
int chil[maxn];
int cnt;
queue<int> Q;
void dfs(int u, int id)
{
num[u] = low[u] = ++cnt;
for(auto edge : adj[u])
{
int v = edge.X, f = edge.Y;
if(!num[v])
{
dfs(v, f);
low[u] = min(low[u], low[v]);
if(low[v]> num[u])
{
isB[f] = true;
}
}
else if(f != id) low[u] = min(low[u], num[v]);
}
}
void play(int u)
{
bcc[u] = cnt;
for(auto edge : adj[u])
{
int v = edge.X, id = edge.Y;
if(!isB[id] && !bcc[v]) play(v);
}
}
void dfsT(int u, int p)
{
int has = 0;
for(auto edge : tree[u])
{
int v = edge.X, id = edge.Y;
if(v == p) continue;
dp[0][v] = u;
dep[v] = 1+dep[u];
link[v] = id;
has = 1;
dfsT(v, u);
chil[u]++;
}
if(!has) Q.push(u);
}
int LCA(int u, int v)
{
if(dep[u]< dep[v]) swap(u, v);
for(int i = 20; i>= 0; i--)
{
int k = dp[i][u];
if(dep[k]>= dep[v]) u = k;
}
if(u == v) return u;
for(int i = 20; i>= 0; i--)
{
int a = dp[i][u], b = dp[i][v];
if(a == b) continue;
u = a; v = b;
}
return dp[0][u];
}
int main()
{
//#ifndef atom freopen(".in", "r", stdin); freopen(".out", "w", stdout); #endif
int n, m; cin >> n >> m;
for(int i = 1; i<= m; i++)
{
scanf("%d %d", &e[i].X, &e[i].Y);
if(e[i].X == e[i].Y) continue;
adj[e[i].X].pb(ii(e[i].Y, i));
adj[e[i].Y].pb(ii(e[i].X, i));
}
for(int i = 1; i<= n; i++) if(!num[i]) dfs(i, 0);
//for(int i = 1; i<= m; i++) printf("%d ", isB[i]); printf("\n");
memset(num, 0, sizeof num);
cnt = 0;
for(int i = 1; i<= n; i++) if(!bcc[i]){ cnt++; play(i); }
//for(int i = 1; i<= n; i++) printf("%d ", bcc[i]); printf("\n");
for(int i = 1; i<= m; i++)
{
if(isB[i])
{
int u = e[i].X, v = e[i].Y;
//printf("(%d, %d) is (%d, %d)\n", u, v, bcc[u], bcc[v]);
tree[bcc[u]].pb(ii(bcc[v], i));
tree[bcc[v]].pb(ii(bcc[u], i));
}
}
for(int i = 1; i<= cnt; i++) if(!dep[i]) { dep[i]++; dfsT(i, 0); }
for(int i = 1; i<= 20; i++)
{
for(int j = 1; j<= cnt; j++) dp[i][j] = dp[i-1][dp[i-1][j]];
}
int p; cin >> p;
while(p--)
{
int a, b; cin >> a >> b;
a = bcc[a], b = bcc[b];
if(a == b) continue;
sw[a]++; sw[b]--;
}
while(!Q.empty())
{
int u = Q.front(); Q.pop();
int p = dp[0][u];
sw[p] += sw[u];
chil[p]--;
if(p && chil[p] == 0) Q.push(p);
if(sw[u]> 0)
{
int id = link[u];
if(bcc[e[id].X] == u) ans[id] = 1;
else ans[id] = -1;
}
else if(sw[u]< 0)
{
int id = link[u];
if(bcc[e[id].X] == u) ans[id] = -1;
else ans[id] = 1;
}
}
for(int i = 1; i<= m; i++)
{
if(ans[i] == 1) printf("R");
else if(ans[i] == -1) printf("L");
else printf("B");
}
printf("\n");
}
