#include <iostream>
#include <cstdint>
#include <array>

using namespace std;

static inline constexpr const char* solve(const char S[3][4]) noexcept
{
	for (uint32_t i = 0; i != 2; ++i)
		if (S[i][0] == S[i + 1][0])
			return "No";

	for (uint32_t i = 0; i != 3; ++i)
		for (uint32_t j = 0; j != 2; ++j)
			if (S[i][j] == S[i][j + 1])
				return "No";

	return "Yes";
}

int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	
	uint32_t i;
	char S[3][4];
	for (i = 0; i != 3; ++i)
		cin >> S[i];

	cout << solve(S) << '\n';
	return 0;
}