#include <bits/stdc++.h>
using namespace std;

struct UnionFind {
    vector<int> par;
    vector<int> size;
    UnionFind(int n) {
        par.resize(n);
        size.resize(n,1);
        for(int i = 0; i < n; i++) {
            par[i] = i;
        }
    }
    int find(int x) {
        if(par[x] == x) {
            return x;
        }
        return par[x] = find(par[x]);
    }
    bool same(int x, int y) {
        return find(x) == find(y);
    }
    int consize(int x) {
        return size[find(x)];
    }
    bool unite(int x, int y) {
        x = find(x);
        y = find(y);
        if(x == y) {
            return false;
        }
        if(size[x] > size[y]) {
            swap(x,y);
        }
        par[x] = y;
        size[y] += size[x];
        return true;
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t;
    cin >> t;
    while(t--) {
        int N;
        cin >> N;
        vector<char>C(N);
        vector<int>D(N);
        UnionFind uf(2*N+3);
        for(int i = 0; i < N; i++) {
            cin >> C[i] >> D[i];
            D[i]--;
            for(int j = 0; j < 3; j++) {
                if("RGB"[j] == C[i]) uf.unite(N+j,i);
            }
            uf.unite(N+3+D[i],i);
        }
        set<int>st;
        for(int i = 0; i < N; i++) {
            st.insert(uf.find(i));
        }
        cout << ((st.size() == 1)?"YES":"NO") << "\n";
    }
}