fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut boxes = (0..n).map(|_| {
            let mut temp = String::new();
            std::io::stdin().read_line(&mut temp).ok();
            let mut temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
            temp.sort();
            (temp[2], temp[1], temp[0])
        })
        .collect::<Vec<_>>();

    boxes.sort();
    let mut dp = vec![1usize; n];
    for i in 1..n {
        let (rx, ry, rz) = boxes[i];
        for j in 0..i {
            let (lx, ly, lz) = boxes[j];
            if lx < rx && ly < ry && lz < rz {
                dp[i] = dp[i].max(dp[j]+1);
            }
        }
    }
    println!("{}", dp.iter().max().unwrap());
}