fn main() {
    let grid = (0..3).map(|_| {
            let mut temp = String::new();
            std::io::stdin().read_line(&mut temp).ok();
            let temp = temp.trim();
            temp.chars().collect::<Vec<_>>()
        })
        .collect::<Vec<_>>();

    let odds = (0..3).map(|i| (0..3).filter(|&j| (i+j) % 2 == 1).fold(true, |x, y| x && (grid[0][1] == grid[i][y]))).fold(true, |x, y| x && y);
    let evens = (0..3).map(|i| (0..3).filter(|&j| (i+j) % 2 == 0).fold(true, |x, y| x && (grid[0][0] == grid[i][y]))).fold(true, |x, y| x && y);
    if odds && evens && (grid[0][0] != grid[0][1]) {
        println!("Yes");
    } else {
        println!("No");
    }
}