#include<stdio.h>
int main()
{
	int n = 3;
	int i, j;
	char s[4][4];
	for (i = 0; i < n; i++)
		scanf("%s", &s[i]);
	int c = 0;
	for (i = 0; i < n; i++)
		for (j = 0; j < n - 1; j++)
			if (s[i][j] == s[i][j + 1])
				c++;
	for (i = 0; i < n - 1; i++)
		for (j = 0; j < n; j++)
			if (s[i][j] == s[i + 1][j])
				c++;
	if (c > 0)
		printf("No\n");
	else
		printf("Yes\n");
	return 0;
}