#include <bits/stdc++.h>
using namespace std;
#define int long long
constexpr int N = 2e5 + 7, M = 11;
constexpr int inf = 1E18, mod = 998244353;
int n;
map<string, vector<string>> G;
map<string, string> pre;
vector<string> ss;
map<string, bool> vis;
inline int bfs(string st, string ed) {
    queue<string> q;
    q.push(st);
    map<string, int> dis;
    map<string, bool> V;
    while(q.size()) {
        auto u = q.front();
        q.pop();
        int len = G[u].size();
        for (int i = 0; i < len; i ++) {
            string p = G[u][i];
            if(V[p]) continue;
            V[p] = true;
            dis[p] = dis[u] + 1;
            pre[p] = u;
            q.push(p);
            if(p == ed) return dis[p];
        }
    }
    return -1;
}
inline void Main() {
    cin >> n;
    for (int i = 1; i <= n; i ++) {
        string s1, s2, s3, s4;
        cin >> s1 >> s2 >> s3 >> s4;
        G[s1 + " " + s2].push_back(s3 + " " + s4);
        vis[s1 + " " + s2] = true;
        vis[s3 + " " + s4] = true;
    }
    int mn = 0x3f3f3f3f;
    string ans1 = "", ans2 = "";
    for (auto [x, y] : vis) {
        string st = x, ed;
        int len = x.size();
        if(x.back() == '0') {
            ed = x.substr(0, len - 1) + "1";
        }else ed = x.substr(0, len - 1) + "0";
        int d = bfs(st, ed);
        if(d != -1) {
            if(d < mn) {
                mn = d, ans1 = st, ans2 = ed;
            }
        }
    }
    bfs(ans1, ans2);
    string now = ans2;
    while(1) {
        ss.push_back(now);
        if(now == ans1) break;
        now = pre[now];
    }
    // cout << ss << '\n';
    reverse(ss.begin(), ss.end());
    for (int i = 0; i < ss.size(); i ++) {
        string p = ss[i];
        cout << p << " ";
        if(i != 0 && i != ss.size() - 1) cout << p << " ";
    }
    cout << "= " << ans1 << " " << ans2 << '\n';
}
signed main() {    
    cin.tie(nullptr)->sync_with_stdio(false);
    int T = 1; 
    while(T --) Main();
    return 0;
}