#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define MP make_pair
#define all(x) x.begin(),x.end()
#define Hagry ios::sync_with_stdio(false);cout.tie(NULL);cin.tie(NULL);

using namespace std;
using ll = long long;
using pi = pair<int, int>;
using vi = vector<int>;
using vpi = vector<pair<int, int>>;
using vvi = vector<vector<int>>;

const int OO = 1e9 + 5;
const int N = 1e3 + 5;

struct Edge {
    int a, b;
    char label;

    Edge() {}

    Edge(int a, int b, char label) : a(a), b(b), label(label) {}

    bool operator<(const Edge &other) {
        return label < other.label;
    }
};

vector<Edge> adjOrg[N];
vector<Edge> adjHid[N];

void print(string &s) {
    cout << s;
    cout.flush();
}

map<string, int> id;

int construct(char parDir) {
    string art, dirs;
    cin >> art >> dirs;
    if (id.find(art) != id.end()) {
        string curArt = art;
        if (parDir != '.') {
            string command = "W  \n";
            command[2] = parDir;
            print(command);
            cin >> art >> dirs;
        }
        return id[curArt];
    }

    int newID = id.size() + 1;
    id[art] = newID;
    if (id.size() > 1000)return -1;

    int curID = id[art];
    for (auto c:dirs) {
        string command = "W  \n";
        command[2] = c;
        print(command);
        int to = construct(c);
        if (to == -1)return -1;
        adjHid[curID].pb(Edge(curID, to, c));
    }

    if (parDir != '.') {
        string command = "W  \n";
        command[2] = parDir;
        print(command);
        cin >> art >> dirs;
    }

    return curID;
}

bool dfs(int i, int orgI, map<int, int> &mp) {
    string dirsHid, dirsOrg;
    for (auto e:adjHid[i])
        dirsHid.pb(e.label);
    for (auto e:adjOrg[orgI])
        dirsOrg.pb(e.label);
    sort(all(dirsHid));
    sort(all(dirsOrg));
    if (dirsHid != dirsOrg)
        return false;

    if (mp.find(i) != mp.end())
        return mp[i] == orgI;
    mp[i] = orgI;
    for (int ind = 0; ind < adjHid[i].size(); ++ind) {
        if (!dfs(adjHid[i][ind].b, adjOrg[orgI][ind].b, mp))
            return false;
    }
    return true;
}

void TC() {
    int n;
    cin >> n;

    for (int i = 1; i <= n; ++i) {
        int m;
        cin >> m;
        char ch;
        int to;
        while (m--) {
            cin >> ch >> to;
            adjOrg[i].pb(Edge(i, to, ch));
        }
    }

    int pos = construct('.');
    if (pos == -1 || id.size() != n) {
        string command = "R no\n";
        print(command);
        return;
    }

    for (int i = 1; i <= n; ++i) {
        sort(all(adjHid[i]));
        sort(all(adjOrg[i]));
    }
    vi ans;
    for (int i = 1; i <= n; ++i) {
        map<int, int> mp;
        if (dfs(pos, i, mp))
            ans.pb(i);
    }

    if (ans.empty()) {
        string command = "R no\n";
        print(command);
        return;
    } else if (ans.size() == 1) {
        string command = "R " + to_string(ans[0]) + "\n";
        print(command);
        return;
    } else {
        string command = "R ambiguous\n";
        print(command);
        return;
    }
}

int32_t main() {
//#ifndef ONLINE_JUDGE
//    freopen("input.in", "r", stdin); freopen("output.out", "w", stdout);
//#endif
    Hagry
    int t = 1;
//    cin >> t;
    while (t--) {
        TC();
        cout << '\n';
    }
    return 0;
}