#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    string s; cin >> s;
    if(s == "Alice") s = "Akane";
    else s = "Aoi";
    
    if(s == "Akane"){
        int N; cin >> N;
        cout << N-2 << endl;
        vector<vector<int>> Graph(N);
        for(int i=0; i<N-1; i++){
            int u,v; cin >> u >> v;
            u--; v--;
            Graph.at(u).push_back(v);
            Graph.at(v).push_back(u);
        }
        for(int t=0; t<N-2; t++){
            if(t) cout << " ";
            for(int i=0; i<N; i++) if(Graph.at(i).size() == 1){
                int k = Graph.at(i).at(0);
                for(int p=0; ; p++) if(Graph.at(k).at(p) == i){
                    Graph.at(k).erase(Graph.at(k).begin()+p); break;
                }
                cout << k+1;
                Graph.at(i) = {};
                break;
            }
        }         
        cout << endl;
    }
    if(s == "Aoi"){
        int N; cin >> N;
        cout << N-2 << endl;
        vector<int> C(N),A(N-2);
        for(auto &a : A) cin >> a,a--,C.at(a)++;
        for(int i=0; i<N-2; i++){
            int a = A.at(i);
            for(int k=0; k<N; k++) if(C.at(k) == 0){
                cout << a+1 << " " << k+1 << endl;
                C.at(k)++,C.at(a)--,A.at(i) = k; break;
            }
        }
        int a = -1,b = -1;
        for(int i=0; i<N; i++){
            if(C.at(i) == 0){
                if(a == -1) a = i;
                else b = i;
            }
        }
        cout << a+1 << " " << b+1 << endl;
    }
}