#include <cstdio>
#include <queue>

using namespace std;

int main(){
	int N;
	while (scanf("%d", &N) != -1){
		getchar(); // remove first space		

		// main test case
		bool visited[N];
		for (int i=0; i<N; ++i) visited[i] = false; //init
		int karty[13][4];
		for (int i=0; i<13; ++i) for (int j=0; j<4; ++j) karty[i][j] = -1;
		int incid[N][N];
		for (int i=0; i<N; ++i) for (int j=0; j<N; ++j) incid[i][j] = 0;
		
		for (int i=0; i < N; ++i){
			int number = getchar();
			if (number >= '2' && number <= '9') number = number - '0' - 1; // map 2-9 to 1-8
			else if (number == 'A') number = 0; // map A to 0
			else if (number == 'X') number = 9;
			else if (number == 'J') number = 10;
			else if (number == 'Q') number = 11;
			else if (number == 'K') number = 12;
			int letter = getchar();
			if (letter == 'C') letter = 0;
			if (letter == 'D') letter = 1;
			if (letter == 'H') letter = 2;
			if (letter == 'S') letter = 3;
			getchar(); // remove next space/newline
			karty[number][letter] = i; // save index of card
		}
		// create incidence matrix
		//printf("%d\n", karty[1][1]);
		// columns
		for (int j=0; j<4; ++j) 
			for (int i=0; i<13; ++i) {
				if (karty[i][j] != -1){
					for (int k=i+1; k<13; ++k) 
						if (karty[k][j] != -1) { // update incidence matrix
							incid[karty[k][j]][karty[i][j]] = 1;
							incid[karty[i][j]][karty[k][j]] = 1;
						}
				}
			}
		// lines
		for (int i=0; i<13; ++i) 
			for (int j=0; j<4; ++j) {
				if (karty[i][j] != -1){
					for (int k=j+1; k<4; ++k) 
						if (karty[i][k] != -1) { // update incidence matrix
							incid[karty[i][j]][karty[i][k]] = 1;
							incid[karty[i][k]][karty[i][j]] = 1;
						}
				}
			}
		// print incidence matrix 
/*
		for (int i=0; i<N; ++i) {
			for (int j=0; j<N; ++j) {
				printf("%d ", incid[i][j]);
			}
			putchar('\n');
		}
*/
		// breadth search of graph
		queue<int> q;
		q.push(0); // init with first node
		while (!q.empty()){
			int current = q.front();
			q.pop();
			visited[current] = true;
			for (int j=0; j<N; ++j)
				if (visited[j] != true && incid[current][j] == 1)
					q.push(j);
		}
		int counter = 0;
		for (int x=0; x<N; ++x) if (visited[x] == true) counter++;
		printf("%s\n", counter==N ? "YES" : "NO" );
	}
	
	return 0;
}