rt

#include<iostream>
#include<string>
using namespace std;

int T, n, q, o, p, cnt = 0;
string s, t;
char c;


void solve()
{
	cnt = 0;
	cin >> s >> t;
	if(s == t)
	{
		cout << "Yes\n";
	}
	else
	{
		cout << "No\n";
		for(int j = 0;j < n;j++)
		{
			if(s[j] != t[j])
			{
				cnt++;
			}
		}
	}
	for(int i = 0;i < q;i++)
	{
		cin >> o >> p >> c;
		if(s[p-1] != t[p-1])
		{
			cnt--;
		}
		if(o == 0)
		{
			s[p-1] = c;
		}
		else if(o == 1)
		{
			t[p-1] = c;
		}
		if(s[p-1] != t[p-1])
		{
			cnt++;
		}
		if(cnt == 0)
		{
			cout << "Yes\n";
		}
		else
		{
			cout << "No\n";
		}
	}
	return;
}

void getinit()
{
	for(int i = 0;i < T;i++)
	{
		cin >> n >> q;
		solve();
	}
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> T;
	getinit();
	return 0;
}