fn main() {
    input! {
        n: usize,
        k: i64,
        s: [String; 2 * n],
        c: [[i64; 2 * n]; 2 * n],
    }

    let bcnt = s
        .iter()
        .map(|r|
            r.chars().filter(|&c| c == '#').count()
        )
        .sum();

    let f_nosym = || -> i64 {
        let mut sorted = c.concat();
        sorted.sort();
        sorted.reverse();
        sorted.iter().take(bcnt).sum()
    };

    let f_sym = || -> i64 {
        if bcnt % 2 == 1 {
            return i64::MIN;
        }

        let mut a = Vec::new();
        for i in 0..2*n {
            for j in 0..n {
                a.push(c[i][j] + c[i][2 * n - 1 - j]);
            }
        }

        a.sort();
        a.reverse();

        k + a.iter().take(bcnt / 2).sum::<i64>()
    };

    let ans = std::cmp::max(f_nosym(), f_sym());

    println!("{}", ans);
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}
 
#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}
 
#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------