#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
#define ff first
#define ss second
int N, M, P;
vector<pair<pii, bool> > edge[100005];
int dfn[100005], dfnn, low[100005];
char ans[100005];
bool vis[100005];
void dfs(int x) {
low[x] = dfn[x] = ++dfnn;
for (auto i : edge[x]) {
if (dfn[i.ff.ff]) {
if (!vis[i.ff.ss]) low[x] = min(low[x], dfn[i.ff.ff]);
vis[i.ff.ss] = 1;
continue;
}
vis[i.ff.ss] = 1;
dfs(i.ff.ff);
low[x] = min(low[x], low[i.ff.ff]);
}
}
int cn, cpn[100005], dep[100005], spt[17][100005];
pii par[100005];
bool dir[100005];
void dfs2(int x, int c) {
cpn[x] = c;
vis[x] = 1;
for (auto i : edge[x]) {
if (vis[i.ff.ff]) continue;
if (low[i.ff.ff] == dfn[i.ff.ff]) {
dep[++cn] = dep[c] + 1;
par[cn] = pii(c, i.ff.ss);
dir[cn] = i.ss;
spt[0][cn] = c;
dfs2(i.ff.ff, cn);
}
else dfs2(i.ff.ff, c);
}
}
int upa[100005];
int fnd(int x) {return x == upa[x] ? x : upa[x] = fnd(upa[x]);}
void uni(int x, int y) {
x = fnd(x), y = fnd(y);
if (x == y) return;
upa[y] = x;
}
int lca(int x, int y) {
if (dep[x] < dep[y]) swap(x, y);
for (int i = 16; i >= 0; --i) if (dep[spt[i][x]] >= dep[y]) x = spt[i][x];
if (x == y) return x;
for (int i = 16; i >= 0; --i) if (spt[i][x] != spt[i][y]) x = spt[i][x], y = spt[i][y];
return spt[0][x];
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> N >> M;
for (int i = 0; i < M; ++i) {
int x, y; cin >> x >> y;
edge[x].emplace_back(pii(y, i), 1);
edge[y].emplace_back(pii(x, i), 0);
}
for (int i = 1; i <= N; ++i) if (!dfn[i]) dfs(i);
memset(vis, 0, sizeof(vis));
for (int i = 1; i <= N; ++i) if (!vis[i]) dep[++cn] = 1, dfs2(i, cn);
for (int i = 1; i < 17; ++i) for (int j = 1; j <= cn; ++j) spt[i][j] = spt[i-1][spt[i-1][j]];
iota(upa, upa + cn + 1, 0);
cin >> P;
for (int i = 0; i < P; ++i) {
int x, y; cin >> x >> y;
x = cpn[x], y = cpn[y];
int l = lca(x, y);
for (int v = x; dep[par[fnd(v)].ff] >= dep[l]; ans[par[fnd(v)].ss] = (dir[fnd(v)] ? 'L' : 'R'), uni(par[fnd(v)].ff, v), v = fnd(v));
for (int v = y; dep[par[fnd(v)].ff] >= dep[l]; ans[par[fnd(v)].ss] = (dir[fnd(v)] ? 'R' : 'L'), uni(par[fnd(v)].ff, v), v = fnd(v));
}
for (int i = 0; i < M; ++i) cout << ((ans[i] != 'L' && ans[i] != 'R') ? 'B' : ans[i]);
return 0;
}
