#include<stdio.h>
#include<string>
#include<iostream>
#include<algorithm>
#include<vector>
#include<map>
using namespace std;
map<char,char> mleft;
map<char,char> mright;
void preorder(char now){
if(now=='.') return;
cout<<now;
preorder(mleft[now]);
preorder(mright[now]);
}
void inorder(char now){
if(now=='.') return;
inorder(mleft[now]);
cout<<now;
inorder(mright[now]);
}
void postorder(char now){
if(now=='.') return;
postorder(mleft[now]);
postorder(mright[now]);
cout<<now;
}
int main(){
int N;
cin>>N;
for(int x=0;x<N;x++){
string input,input2,input3;
cin>>input>>input2>>input3;
mleft[input[0]]=input2[0];
mright[input[0]]=input3[0];
}
preorder('A');
cout<<'\n';
inorder('A');
cout<<'\n';
postorder('A');
}
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