#include <iostream>
#include <fstream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <cstdlib>
#include <cstdio>
#include <string>
#include <cstring>
#include <cassert>
#include <utility>
#include <iomanip>

using namespace std;

const int MAXN = 5 * 1050;

struct edge {
	int to;
	bool used;
	bool bad;
};

int n;
char ss[5];
vector <edge> e;
vector <int> g[MAXN];
int in[MAXN], out[MAXN];
vector <int> ans;
int s = -1, t = -1;

void dfs(int v) {
	for (int i = 0; i < (int) g[v].size(); i++) {
		int ind = g[v][i];
		int to = e[ind].to;
		if (e[ind].used)
			continue;
		e[ind].used = true;
		dfs(e[ind].to);
	}
	ans.push_back(v);
}

int main() {
	//assert(freopen("input.txt","r",stdin));
	//assert(freopen("output.txt","w",stdout));

	scanf("%d\n", &n);

	for (int i = 1; i <= n; i++) {
		gets(ss);
		int from = (int) ss[0] * 10 + (int) ss[1];
		int to = (int) ss[1] * 10 + (int) ss[2];
		//cerr << from << " " << to << endl;
		edge ed;
		ed.to = to;
		ed.used = false;
		e.push_back(ed);
		g[from].push_back( (int) e.size() - 1);
		out[from]++; in[to]++;
	}

	for (int i = 0; i < 3000; i++) {
		if ((in[i] % 2 == 0) && (out[i] % 2 == 0))
			continue;
		if (out[i] > in[i]) {
			if (s == -1) {
				s = i;
			}
			else {
				puts("NO");
				return 0;
			}
		}
		if (in[i] > out[i]) {
			if (t == -1) {
				t = i;
			}
			else {
				puts("NO");
				return 0;
			}
		}
	}

	if (s == -1 || t == -1) {
		puts("NO");
		return 0;
	}

	edge ed;
	ed.to = s;
	ed.bad = true;
	ed.used = true;
	e.push_back(ed);
	g[t].push_back( (int) e.size() - 1);

	dfs(s);

	puts("YES");

	int len = (int) ans.size();

	for (int i = 0; i < len; i++)
		cout << ans[i] << " ";
	cout << endl;

	int st = 0;
	for (int i = 0; i < len; i++) {
		if (i + 1 < len && ans[i] == t && ans[i + 1] == s) {
			st = i + 1;
			break;
		}
	}

	for (int j = 0; j < len - 1; j++) {
		int from = ans[(st + j) % len], to = ans[(st + j + 1) % len];
		if (j == 0) {
			putchar(from / 10);
			putchar(from % 10);
		}
		putchar(to % 10);
	}

	cout << endl;

	return 0;
}