#include <algorithm>
#include <cstdio>
#include <vector>

constexpr int N = 200005;

int n;

std::vector<int> G[N];

int tp[N], dep[N];

struct node
{
    int tp, dep, id;
};

void dfs1(int u, int fa)
{
    for (int v : G[u])
    {
        if (v == fa) continue;
        dep[v] = dep[u] + 1;
        dfs1(v, u);
    }
}

using pii = std::pair<int, int>;

std::vector<pii> ans;

node dfs2(int u, int fa)
{
    node res{0, 0, 0};
    std::vector<pii> sub[4];
    sub[tp[u]].emplace_back(dep[u], u);
    for (int v : G[u])
    {
        if (v == fa) continue;
        node t = dfs2(v, u);
        if (t.tp == -1) return node{-1, -1, -1};
        if (t.tp > 0) sub[t.tp].emplace_back(t.dep, t.id);
    }
    for (int i = 1; i <= 3; ++i) std::sort(sub[i].begin(), sub[i].end(), std::greater<pii>());
    if (!sub[3].empty())
    {
        int cnt = 1;
        for (int i = 1; i < sub[3].size(); ++i)
        {
            if (sub[3][i].first != sub[3][i - 1].first)
            {
                if (cnt & 1)
                {
                    if (res.tp) return node{-1, -1, -1};
                    res = node{3, sub[3][i - 1].first, sub[3][i - 1].second};
                }
                for (int j = i - cnt; j < i - 1; j = 2)
                    ans.emplace_back(sub[3][j].second, sub[3][j + 1].second);
                cnt = 1;
            }
            else
                cnt++;
        }
        for (int j = sub[3].size() - cnt; j < sub[3].size() - 1; j += 2)
            ans.emplace_back(sub[3][j].second, sub[3][j + 1].second);
        if (cnt & 1)
        {
            if (res.tp != 0) return (node){-1, -1, -1};
            res = (node){3, sub[3][sub[3].size() - 1].first, sub[3][sub[3].size() - 1].second};
        }
    }
    if (sub[1].size() == sub[2].size())
    {
        for (int i = 0; i < sub[1].size(); i++)
        {
            if (sub[1][i].first <= sub[2][i].first) return (node){-1, -1, -1};
            ans.emplace_back(sub[1][i].second, sub[2][i].second);
        }
    }
    else if (sub[1].size() > sub[2].size())
    {
        int poi = sub[1].size() - 1;
        for (int i = sub[2].size() - 1; i >= 0; i--)
        {
            while (poi >= 0 && sub[1][poi].first <= sub[2][i].first)
            {
                if (res.tp != 0) return node{-1, -1, -1};
                res = node{1, sub[1][poi].first, sub[1][poi].second}, poi--;
            }
            if (poi >= 0 && sub[1][poi].first > sub[2][i].first)
            {
                ans.emplace_back(sub[1][poi].second, sub[2][i].second);
                poi--;
            }
            else
                return node{-1, -1, -1};
        }
        while (poi >= 0)
        {
            if (res.tp != 0) return node{-1, -1, -1};
            res = node{1, sub[1][poi].first, sub[1][poi].second}, poi--;
        }
    }
    else
    {
        int poi = 0;
        for (int i = 0; i < sub[1].size(); i++)
        {
            while (poi < sub[2].size() && sub[1][i].first <= sub[2][poi].first)
            {
                if (res.tp != 0) return node{-1, -1, -1};
                res = node{2, sub[2][poi].first, sub[2][poi].second}, poi++;
            }
            if (poi < sub[2].size() && sub[1][i].first > sub[2][poi].first)
            {
                ans.emplace_back(sub[1][i].second, sub[2][poi].second);
                poi++;
            }
            else
                return (node){-1, -1, -1};
        }
        while (poi < sub[2].size())
        {
            if (res.tp != 0) return (node){-1, -1, -1};
            res = (node){2, sub[2][poi].first, sub[2][poi].second}, poi++;
        }
    }
    if (u == 1 && res.tp) return (node){-1, -1, -1};
    return res;
}

int main()
{
    scanf("%d", &n);
    for (int i = 1; i < n; i++)
    {
        int u, v;
        char str[20];
        scanf("%d%d%s", &u, &v, str);
        G[u].push_back(v);
        G[v].push_back(u);
        if (str[0] == 'C')
            tp[u] = 1;
        else if (str[0] == 'D')
            tp[u] = 2;
        else if (str[0] == 'T')
            tp[u] = 3;
    }
    dfs1(1, 0);
    node res = dfs2(1, 0);
    if (res.tp == -1)
        puts("NO");
    else
    {
        puts("YES");
        for (int i = 0; i < ans.size(); i++) printf("%d %d\n", ans[i].first, ans[i].second);
    }
}

answer.code: In function ‘node dfs2(int, int)’:
answer.code:44:79: error: ‘greater’ is not a member of ‘std’
   44 |     for (int i = 1; i <= 3; ++i) std::sort(sub[i].begin(), sub[i].end(), std::greater<pii>());
      |                                                                               ^~~~~~~
answer.code:44:90: error: expected primary-expression before ‘>’ token
   44 |     for (int i = 1; i <= 3; ++i) std::sort(sub[i].begin(), sub[i].end(), std::greater<pii>());
      |                                                                                          ^
answer.code:44:92: error: expected primary-expression before ‘)’ token
   44 |     for (int i = 1; i <= 3; ++i) std::sort(sub[i].begin(), sub[i].end(), std::greater<pii>());
      |                                                                                            ^
answer.code: In function ‘int main()’:
answer.code:134:10: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  134 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
answer.code:139:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  139 |         scanf("%d%d%s", &u, &v, str);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~