#include <iostream>
#include<vector>

using namespace std;
vector <int> v;
vector <vector <int>> c;
vector <int> vis;
void DFS(int n)
{
    cout<<n<<endl;
    for(int i=0;i<c[n].size();i++)
    {
        if(vis[n]==0 && 64<c[n][i]<91)
        {
            vis[n]=1;
            DFS(c[n][i]);
        }
    }
}
int main() {
    int a;
    char x,y,z,t;
    cin >>a;
    v.resize(65+a);
    c.resize(65+a);
    vis.resize(65+a);
    for(int i=0;i<a;i++)
    {
            cin >>x>>y>>z;
            c[x].push_back(y);
            c[x].push_back(z);
            c[y].push_back(x);
            c[z].push_back(x);
    }
    t='A';
    DFS(t);
}