#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define sz(x) int32_t(x.size())
#define all(x) x.begin(),x.end()
#define pb push_back
#define F first
#define S second
const int N = 1e5+40;
int n, d, q, id[N][3], comp[N], nxt = 0, cur;
bool vis[N];
string s;
vector<int> adj[N], rev[N], ids;
int id1[N], id2[N];
char ch1[N], ch2[N];

int get(int i, char x) {
    return id[i][int(x - 'a')];
}

void ade(int u, int v) {
    adj[u].push_back(v);
    rev[v].push_back(u);
}

void init() {
    cur = 0;
    for (int i = 0; i < N; i++) {
        vis[i] = false;
        adj[i].clear();
        rev[i].clear();
    }
    nxt = 0;
}

vector<int> topo;

void dfs_topo(int u) {
    if (vis[u])return;
    vis[u] = true;
    for (auto &v : adj[u]) {
        dfs_topo(v);
    }
    topo.push_back(u);
}

void get_scc(int u) {
    if (vis[u])return;
    vis[u] = true;
    comp[u] = cur;
    for (auto &v : rev[u]) {
        get_scc(v);
    }
}

void val() {
    init();
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < 3; j++) {
            if (j == int(s[i] - 'a')) {
                id[i][j] = -1;
                continue;
            }
            id[i][j] = nxt++;
        }
    }
    for (int i = 0; i < q; i++) {
        if (s[id1[i]] == ch1[i])continue;
        if (s[id2[i]] == ch2[i]) {
            int f = 0, sc = 0;
            while (id[id1[i]][f] == -1)f++;
            while (id[id1[i]][sc] == -1 || sc == f)sc++;
            if (f != int(ch1[i]-'a'))swap(f, sc);
            ade(id[id1[i]][f], id[id1[i]][sc]);
            continue;
        }
        int x = id[id1[i]][int(ch1[i]-'a')];
        int y = id[id2[i]][int(ch2[i]-'a')];
        ade(x, y);
        ade((y^1), (x^1));
    }
    for (int i = 0; i < nxt; i++) {
        dfs_topo(i);
    }
    memset(vis, 0, sizeof vis);
    while (!topo.empty()) {
        int u = topo.back();
        topo.pop_back();
        if (!vis[u]) {
            get_scc(u);
            cur++;
        }
    }
    for (int i = 0; i < n; i++) {
        int f = 0, sc = 0;
        while (id[i][f] == -1)f++;
        while (id[i][sc] == -1 || sc == f)sc++;
        if (comp[id[i][f]] == comp[id[i][sc]])return;
    }
    string ans = s;
    for (int i = 0; i < n; i++) {
        int f = 0, sc = 0;
        while (id[i][f] == -1)f++;
        while (id[i][sc] == -1 || sc == f)sc++;
        ans[i] = (comp[id[i][f]] > comp[id[i][sc]] ? char(f+'A') : char(sc+'A'));
        ans[i] = tolower(ans[i]);
    }
    for (int i = 0; i < q; i++) {
        if (ans[id1[i]] == ch1[i]) {
            if (ans[id2[i]] != ch2[i]) {
                cout<<ans<<endl;
                assert(false);
            }
        }
    }
    for (int i = 0; i < n; i++) {
        int f = 0, sc = 0;
        while (id[i][f] == -1)f++;
        while (id[i][sc] == -1 || sc == f)sc++;
        cout << (comp[id[i][f]] > comp[id[i][sc]] ? char(f+'A') : char(sc+'A'));
    }
    exit(0);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> d >> s >> q;
    for (int i = 0; i < n; i++) {
        if (s[i] == 'x')ids.push_back(i);
    }
    for (int i = 0; i < q; i++) {
        cin >> id1[i] >> ch1[i] >> id2[i] >> ch2[i];
        --id1[i], --id2[i];
        ch1[i] = tolower(ch1[i]);
        ch2[i] = tolower(ch2[i]);
    }
    for (int i = 0; i < (1 << sz(ids)); i++) {
        for (int j = 0; j < sz(ids); j++) {
            char c = 'a';
            if ((i & (1 << j)))c = 'b';
            s[ids[j]] = c;
        }
        val();
    }
    cout << -1;
}