#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5+10;
const int maxl = 20;
typedef pair<int, int> pii;
int n, m;
int in[maxn], low[maxn], tt;
int comp[maxn], bcc;
int pai[maxn], nivel[maxn];
int tab[maxn][maxl];
int menor[2][maxn];
int ans[maxn];
bool bridge[maxn], mark_tree[maxn];
pii edge[maxn], edgeP[maxn];
vector<pair<int, pii>> grafo[maxn], tree[maxn];
void find_bridge(int u, int ant)
{
in[u] = low[u] = ++tt;
for (auto pp: grafo[u])
{
int v = pp.first, e = pp.second.first;
if (e == ant) continue;
if (in[v])
{
low[u] = min(low[u], in[v]);
continue;
}
find_bridge(v, e);
if (low[v] > in[u]) bridge[e] = true;
low[u] = min(low[u], low[v]);
}
}
void mark(int u, int cc)
{
comp[u] = cc;
for (auto v: grafo[u])
{
if (comp[v.first] || bridge[v.second.first]) continue;
mark(v.first, cc);
}
}
void dfs(int u, int p)
{
mark_tree[u] = true;
for (auto pp: tree[u])
{
int v = pp.first, e = pp.second.first;
if (v == p) continue;
nivel[v] = nivel[u]+1, pai[v] = u;
edgeP[v] = {e, pp.second.second};
dfs(v, u);
}
}
void build(void)
{
memset(tab, -1, sizeof tab);
for (int i = 1; i <= n; i++)
tab[i][0] = pai[i];
for (int j = 1; j < maxl; j++)
for (int i = 1; i <= n; i++)
if (tab[i][j-1] != -1)
tab[i][j] = tab[tab[i][j-1]][j-1];
}
int lca(int u, int v)
{
if (nivel[u] < nivel[v]) swap(u, v);
for (int i = maxl-1; i >= 0; i--)
if (nivel[u]-(1<<i) >= nivel[v])
u = tab[u][i];
if (u == v) return u;
for (int i = maxl-1; i >= 0; i--)
if (tab[u][i] != -1 && tab[v][i] != -1 && tab[u][i] != tab[v][i])
u = tab[u][i], v = tab[v][i];
return pai[u];
}
int solve1(int u, int p)
{
int m = 1e9+10;
mark_tree[u] = true;
for (auto pp: tree[u])
{
int v = pp.first, e = pp.second.first;
int direct = pp.second.second;
if (v == p) continue;
int x = solve1(v, u);
if (x <= nivel[u])
{
if (direct) ans[e] = 0;
else ans[e] = 1;
}
m = min(m, x);
}
return min(m, menor[1][u]);
}
int solve0(int u, int p)
{
int m = 1e9+10;
mark_tree[u] = true;
for (auto pp: tree[u])
{
int v = pp.first, e = pp.second.first;
int direct = pp.second.second;
if (v == p) continue;
int x = solve0(v, u);
if (x <= nivel[u])
{
if (direct) ans[e] = 1;
else ans[e] = 0;
}
m = min(m, x);
}
return min(m, menor[0][u]);
}
int main(void)
{
scanf("%d %d", &n, &m);
for (int i = 1; i <= m; i++)
{
int u, v;
scanf("%d %d", &u, &v);
edge[i] = {u, v};
if (u != v)
{
grafo[u].push_back({v, {i, 1}});
grafo[v].push_back({u, {i, 0}});
}
ans[i] = 2;
}
for (int i = 1; i <= n; i++)
if (!in[i])
find_bridge(i, 0);
for (int i = 1; i <= n; i++)
if (!comp[i])
mark(i, ++bcc);
for (int i = 1; i <= n; i++)
{
for (auto pp: grafo[i])
{
int v = pp.first, e = pp.second.first;
int direct = pp.second.second;
if (bridge[e]) tree[comp[i]].push_back({comp[v], {e, direct}});
}
}
for (int i = 1; i <= bcc; i++)
{
menor[0][i] = menor[1][i] = 1e9+10;
if (!mark_tree[i])
dfs(i, 0);
}
build();
int p;
scanf("%d", &p);
for (int i = 1; i <= p; i++)
{
int u, v;
scanf("%d %d", &u, &v);
u = comp[u], v = comp[v];
int low = lca(u, v);
menor[1][u] = min(menor[1][u], nivel[low]);
menor[0][v] = min(menor[0][v], nivel[low]);
}
memset(mark_tree, 0, sizeof mark_tree);
for (int i = 1; i <= bcc; i++)
if (!mark_tree[i])
solve1(i, 0);
memset(mark_tree, 0, sizeof mark_tree);
for (int i = 1; i <= bcc; i++)
if (!mark_tree[i])
solve0(i, 0);
for (int i = 1; i <= m; i++)
{
if (ans[i] == 2) printf("B");
else if (ans[i] == 1) printf("R");
else printf("L");
}
printf("\n");
}
