Endless holiday

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 998244353;

void solve() {
    int n, m;
    cin >> n >> m;
    vector<vector<int>> G(n+1);
    bool flg = 0;
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    int len;
    cin >> len;
    vector<string> a(n+1);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        G[i].push_back(i);
        // cout << a[i] << endl;
    }

    vector<vector<int>> f(n+1,vector<int>(len+1));
    auto dfs = [&] (auto&&self, int x, int y) {
        if (flg) return;
        if (f[x][y] == 1) {
            flg = true;
            return;
        } else if (f[x][y] == 2) {
            return;
        }

        f[x][y] = 1;
        for (auto i : G[x]) {
            if (a[i][(y+1)%len] == 'o') {
                self(self,i,(y+1)%len);
            }
        }
        f[x][y] = 2;
    };

    for (int i = 1; i <= n; i++) {
        if (a[i][0] == 'o' && !flg) {
            dfs(dfs,i,0);
        }
    }
    if (flg) {
        cout << "Yes";
    } else {
        cout << "No";
    }
    cout << '\n';
}   

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int tt = 1;
    cin >> tt;
    while (tt--) {
        solve();
    }
    return 0;
}