#include <iostream>
#include <vector>
#include <deque>
#include <cmath>

#define INF 10000

using namespace std;

struct person{
    string name, skill;
    int rank;
    person(string Name, string Skill, int Rank){
        name = Name; skill = Skill; rank = Rank;
    }
};
vector <person> data;
vector <vector <int> > g;
const int MAXN = 2003;
int c[MAXN][MAXN], f[MAXN][MAXN];
int N;
void readData(int &n){
    cin >> n;
    N = 2 * n + 2;
    data.resize(n+1,person("0","0",0));
    g.resize(N+1);
    for (int i=1; i<=n; i++){
        cin >> data[i].name;
        cin >> data[i].skill;
        cin >> data[i].rank;
    }
}
void buildNetwork(int& n){
    for (int i=1; i<=n; i++){
        for (int j=1; j<=n; j++){
            if (abs(data[i].rank - data[j].rank) == 2 && (data[i].skill == "anything" || data[j].skill == "anything" ||
                (data[i].skill == "statements" && data[j].skill == "testdata") || (data[i].skill == "testdata" && data[j].skill == "statements"))){
                g[i].push_back(j + n);
                g[j + n].push_back(i);
                c[i][j + n] = 1;
            }
        }
    }
    for (int i=1; i<=n; i++){
        g[N-1].push_back(i);
        g[i].push_back(N-1);
        c[N-1][i] = 1;
    }
    for (int i=n+1; i<=2*n; i++){
        g[i].push_back(N);
        g[N].push_back(i);
        c[i][N] = 1;
    }
}
bool bfs(int v, deque <int>& turn, vector <int>& lvl){
    int q,to;
    for (q=0; q<g[v].size(); q++){
        to = g[v][q];
        if (c[v][to] - f[v][to] > 0 && lvl[to] == INF){
            lvl[to] = lvl[v] + 1;
            turn.push_back(to);
        }
    }
    turn.pop_front();
    if (!turn.empty()) bfs(*turn.begin(),turn,lvl);
    return lvl[N] != INF;
}
int dfs(int v, vector <int>& pointer, vector <int>& lvl){
    if (v == N){
        return 1;
    }
    int q,to;
    for (q=pointer[v]; q<g[v].size(); q++){
        to = g[v][q];
        if (lvl[v] + 1 == lvl[to] && c[v][to] - f[v][to] > 0 && dfs(to,pointer,lvl)){
            f[v][to] += 1;
            f[to][v] -= 1;
            return 1;
        }
        else{
            pointer[v]++;
        }
    }
    return 0;
}
void findMaxFlow(int &n){
    deque <int> turn;
    vector <int> lvl(N+1);
    vector <int> pointer(N+1);
    while (1){
        turn.push_back(N-1);
        lvl.assign(N+1,INF);
        lvl[N-1]=0;
        if (!bfs(N-1,turn,lvl)) break;
        pointer.assign(N+1,0);
        while (dfs(N-1,pointer,lvl));
    }
    int pairs = 0;
    for (int i=1; i<=n; i++){
        for (int j=n+1+i; j<=2*n; j++){
            if (f[i][j] == 1){
                pairs++;
            }
        }
    }
    cout << pairs << "\n";
    for (int i=1; i<=n; i++){
        for (int j=n+1+i; j<=2*n; j++){
            if (f[i][j] == 1){
                if (data[i].skill != "testdata" && data[j - n].skill != "statements") cout << data[i].name << " " << data[j - n].name << "\n";
                else cout << data[j - n].name << " " << data[i].name << "\n";
            }
        }
    }
}
int main(){
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    int n;
    readData(n);
    buildNetwork(n);
    findMaxFlow(n);
    return 0;
}