#include <bits/stdc++.h>

using namespace std;

int main() {
	string s1, s2, s3;
	cin >> s1 >> s2 >> s3;

	string s = s1 + s2 + s3;
	bool ok = true;
	for (int i = 1; i < 9; i++) {
		if (s[i] == s[i-1]) {
			ok = false;
		}
	}

	if (ok) {
		puts("Yes");
	} else {
		puts("No");
	}

	return 0;
}