//(ᗜ ˰ ᗜ)
// #define NDEBUG
#include <bits/stdc++.h>
using namespace std;
namespace LING
{
#ifdef ONLINE_JUDGE
#define DBG(...) ;
#define dbg(...) ;
#else
#define DBG(x) cout << "! " << #x << " = " << x << endl
#include "debug.h"
#endif
    using ll = long long;
    using db = double;
#define SPO(x) fixed << setprecision(x)
#define FOR(i, l, r) for (ll i = l; i <= (r); ++i)
#define ROF(i, r, l) for (ll i = r; i >= (l); --i)
#define edl '\n'
#define fir first
#define sec second
#define str string
#define pll pair<ll, ll>
#define heap priority_queue
    // constexpr db PI = acos(-1.0);
    // constexpr db EPS = 1.0e-9;
    constexpr long long LNF = 0x3f3f3f3f3f3f3f3fLL;
    constexpr int INF = 0x3f3f3f3f;
    constexpr long long MOD = 998244353;
    constexpr ll MXN = 1e6 + 5;
    ll KSM(ll base, ll exp, ll MOD)
    {
        ll res = 1;
        base %= MOD;
        while (exp)
        {
            if (exp & 1)
                res = (res * base) % MOD;
            base = (base * base) % MOD;
            exp >>= 1;
        }
        return res;
    }
}
using namespace LING;
ll n;
ll a[MXN];
ll d[MXN];
vector<ll> g[MXN];
vector<pll> ans;
void dfs(ll u)
{
    for (auto &v : g[u])
    {
        d[v] = d[u] + 1;
        dfs(v);
    }
}
ll dfs1(ll u)
{
    heap<pll> q[4];
    if (a[u])
        q[a[u]].push({d[u], u});
    for (auto &v : g[u])
    {
        d[v] = d[u] + 1;
        ll tmp = dfs1(v);
        if (tmp)
            q[a[tmp]].push({d[tmp], tmp});
    }
    vector<pll> ve;
    while (q[3].size())
    {
        pll x = q[3].top();
        q[3].pop();
        if (q[3].size() == 0)
        {
            ve.push_back(x);
            break;
        }
        pll y = q[3].top();
        q[3].pop();
        if (x.first == y.first)
            ans.push_back({x.second, y.second});
        else
        {
            ve.push_back(x);
            q[3].push(y);
        }
    }
    // dbg(u);
    // dbg(ve);
    if (abs((ll)q[1].size() - (ll)q[2].size()) > 1)
    {
        cout << "NO" << edl;
        exit(0);
    }
    while (q[1].size() && q[2].size())
    {
        pll x = q[1].top();
        q[1].pop();
        pll y = q[2].top();
        q[2].pop();
        if (x.first <= y.first)
        {
            ve.push_back(x);
            q[2].push(y);
        }
        else
            ans.push_back({x.second, y.second});
    }
    if (q[1].size())
        ve.push_back(q[1].top());
    if (q[2].size())
        ve.push_back(q[2].top());
    // dbg(ve);
    if (ve.size() > 1)
    {
        cout << "NO" << edl;
        exit(0);
    }
    if (ve.size())
        return ve[0].second;
    else
        return 0;
}
void Solve(void)
{
    cin >> n;
    FOR(i, 2, n)
    {
        ll u, v, w;
        str t;
        cin >> u >> v >> t;
        if (t == "Chang")
            w = 1;
        else if (t == "Duan")
            w = 2;
        else if (t == "Tong")
            w = 3;
        else
            w = 0;
        a[u] = w;
        g[v].push_back(u);
    }
    dfs(1);

    // FOR(i, 1, n)
    // cout << d[i] << " \n"[i == n];

    if (dfs1(1))
        cout << "NO" << edl;
    else
    {
        cout << "YES" << edl;
        for (auto &i : ans)
            cout << i.first << ' ' << i.second << edl;
    }
    return;
}
int main(void)
{
    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    // #ifndef ONLINE_JUDGE
    // freopen("cin.txt","r",stdin);
    // freopen("cout.txt","w",stdout);
    // #endif

    int t = 1;
    // cin >> t;
    while (t--)
        Solve();
    return 0;
}