/* -*- coding: utf-8 -*-
 *
 * 2148.cc:  No.2148 ひとりUNO - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000 + 3;

enum { B, G, R };

/* typedef */

struct UFT {
  vector<int> links, ranks, sizes;
  UFT() {}

  void init(int n) {
    links.resize(n);
    for (int i = 0; i < n; i++) links[i] = i;
    ranks.assign(n, 1);
    sizes.assign(n, 1);
  }

  int root(int i) {
    int i0 = i;
    while (links[i0] != i0) i0 = links[i0];
    return (links[i] = i0);
  }

  int rank(int i) { return ranks[root(i)]; }
  int size(int i) { return sizes[root(i)]; }
  bool same(int i, int j) { return root(i) == root(j); }

  int merge(int i0, int i1) {
    int r0 = root(i0), r1 = root(i1), mr;
    if (r0 == r1) return r0;
    if (ranks[r0] == ranks[r1]) {
      links[r1] = r0;
      sizes[r0] += sizes[r1];
      ranks[r0]++;
      mr = r0;
    }
    else if (ranks[r0] > ranks[r1]) {
      links[r1] = r0;
      sizes[r0] += sizes[r1];
      mr = r0;
    }
    else {
      links[r0] = r1;
      sizes[r1] += sizes[r0];
      mr = r1;
    }
    return mr;
  }
};

/* global variables */

int gids[MAX_N];
UFT uft;

/* subroutines */

inline int c2i(char c) {
  return (c == 'B') ? B : (c == 'G') ? G : (c == 'R') ? R : -1;
}

inline int allocid(int x, int &gn) {
  return (gids[x] >= 0) ? gids[x] : (gids[x] = gn++);
}

/* main */

int main() {
  int tn;
  scanf("%d", &tn);

  while (tn--) {
    int n;
    scanf("%d", &n);

    int gn = 0;
    fill(gids, gids + n + 3, -1);
    uft.init(n + 3);

    for (int i = 0; i < n; i++) {
      char s[4];
      int d;
      scanf("%s%d", s, &d);

      int u = allocid(c2i(s[0]) + n, gn);
      int v = allocid(d - 1, gn);
      uft.merge(u, v);
    }

    if (uft.size(0) == gn) puts("YES");
    else puts("NO");
  }
  return 0;
}