// Starcraft 2 enjoyer //
#include <bits/stdc++.h>
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
using namespace std;
#define LSOne(X) ((X) & -(X))
#define int long long
const int N = 1e5 + 5;
const int M = 1e6 + 5;
const int K = 1e3 + 5;
const int LG = 60;
const int INF = 1e18 + 5;
const int B = 1000;
const int MOD = 1e9 + 7;
int n, m, q, cid, id[N], low[N], type[N], cur, binlift[N][LG], depth[N], ans[N], mxu[N], mxd[N];
bool vis[N], bridge[N], chk[N];
vector<pair<int, int>> edges, adj[N], adj2[N];
void dfs1(int c, int l)
{
if (vis[c])
return;
vis[c] = 1;
id[c] = cid;
low[c] = cid++;
for (auto &[i, j] : adj[c])
{
if (j == l)
continue;
if (chk[j])
{
low[c] = min(low[c], id[i]);
continue;
}
chk[j] = 1;
dfs1(i, j);
low[c] = min(low[c], low[i]);
// cout << low[i] << " " << id[i] << " " << id[c] << " " << i << " " << c << "\n";
if (low[i] > id[c])
{
bridge[j] = 1;
// cout << j + 1 << "\n";
}
}
// cout << low[c] << " " << id[c] << " " << c << "\n";
}
void dfs2(int c)
{
if (vis[c])
return;
type[c] = cur;
vis[c] = 1;
id[c] = cid;
low[c] = cid++;
for (auto &[i, j] : adj[c])
{
if (bridge[j])
continue;
chk[j] = 1;
dfs2(i);
}
}
void dfs3(int c, int p)
{
for (auto &[i, id] : adj2[c])
{
if (i == p)
continue;
depth[i] = depth[c] + 1;
binlift[0][i] = c;
for (int x = 1; x < LG; x++)
{
binlift[x][i] = binlift[x - 1][binlift[x - 1][i]];
}
dfs3(i, c);
}
}
pair<int, int> dfs4(int c, int p)
{
pair<int, int> pr = {depth[c] + 1, 0};
for (auto &[i, id] : adj2[c])
{
if (i == p)
continue;
pair<int, int> cur = dfs4(i, c);
// cout << cur.first << " " << cur.second << " " << i << " " << c << "\n";
if (cur.first <= depth[c])
{
if (cur.second == 1) // go up
{
// cout << i << " " << edges[id].first << " " << edges[id].second << "\n";
if (type[edges[id].first] == i)
{
ans[id] = 1;
}
else
{
ans[id] = 2;
}
}
else // go down
{
if (type[edges[id].first] == i)
{
ans[id] = 2;
}
else
{
ans[id] = 1;
}
}
}
else
{
ans[id] = 0;
}
pr = min(pr, cur);
}
if (mxu[c] < depth[c])
{
pr = min(pr, (pair<int, int>){mxu[c], 1});
}
if (mxd[c] < depth[c])
{
pr = min(pr, (pair<int, int>){mxd[c], 2});
}
return pr;
}
int lca(int a, int b)
{
if (depth[a] != depth[b])
{
if (depth[a] < depth[b])
swap(a, b);
int k = depth[a] - depth[b];
for (int x = 0; x < LG; x++)
{
if (k >> x & 1)
{
a = binlift[x][a];
}
}
}
if (a == b)
return a;
for (int x = LG - 1; x >= 0; x--)
{
if (binlift[x][a] != binlift[x][b])
{
a = binlift[x][a];
b = binlift[x][b];
}
}
return binlift[0][a];
}
inline void solve()
{
cin >> n >> m;
for (int x = 0; x < m; x++)
{
int a, b;
cin >> a >> b;
adj[a].push_back({b, x});
adj[b].push_back({a, x});
edges.push_back({a, b});
}
for (int x = 1; x <= n; x++)
{
if (vis[x])
continue;
dfs1(x, -1);
}
for (int x = 1; x <= n; x++)
{
vis[x] = 0;
}
for (int x = 0; x < m; x++)
{
chk[x] = 0;
}
cur = 1;
for (int x = 1; x <= n; x++)
{
if (vis[x])
continue;
dfs2(x);
cur++;
}
for (int x = 0; x < m; x++)
{
if (!bridge[x])
{
ans[x] = 0;
continue;
}
// cout << edges[x].first << " " << edges[x].second << "\n";
int a = type[edges[x].first];
int b = type[edges[x].second];
if (a == b)
continue;
adj2[a].push_back({b, x});
adj2[b].push_back({a, x});
}
dfs3(1, 0);
for (int x = 1; x < cur; x++)
{
mxd[x] = mxu[x] = depth[x];
}
cin >> q;
for (int x = 0; x < q; x++)
{
int a, b, c;
cin >> a >> b;
a = type[a];
b = type[b];
c = lca(a, b);
mxu[a] = min(mxu[a], depth[c]);
mxd[b] = min(mxd[b], depth[c]);
}
// for(int x = 1; x < cur; x++)
// {
// cout << mxu[x] << " " << mxd[x] << "\n";
// }
// cout << "\n";
dfs4(1, 0);
for (int x = 0; x < m; x++)
{
if (ans[x] == 0)
{
cout << 'B';
}
else if (ans[x] == 1)
{
cout << 'R';
}
else
{
cout << 'L';
}
}
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
for (int x = 1; x <= t; x++)
{
solve();
}
return 0;
}
