#include<bits/stdc++.h>
using namespace std;
int n;
char start,c;
pair<char, char> shu[80];
void dfs(char c){
	if(ispunct(c))
		return;
	putchar(c);
	dfs(shu[c].second);
	dfs(shu[c].first);
}
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;++i){
		scanf("%c",&c);
		if(i==1)
			start=c;
shu[c]=pair<char,char>(scanf("%s"),scanf("%s"));//这里	
	}dfs(start);
	return 0;
}

不用scanf会超时