#![allow(non_snake_case)]
#![allow(unused_imports)]
// use itertools::Itertools;
// use proconio::input;
// use proconio::marker::*;
use std::cmp::Reverse;
use std::collections::*;

fn main() {
    input! {
        n:usize,
        K:usize,
        sc:[(String,usize);n],
    }

    let mut sc = sc;
    sc.push(("".to_string(), 0));
    let mut cnts = vec![[0; 3]; n + 1];
    let mut costs = vec![0; n + 1];
    for i in 0..n {
        costs[i] = sc[i].1;
        for si in sc[i].0.chars() {
            cnts[i][toidx(si)] += 1;
        }
    }

    let mut ans = INF;
    for i in 0..=n {
        for j in 0..=n {
            for k in 0..=n {
                let mut cost = 0;
                let rem = K.saturating_sub(cnts[i][0]);
                cost += costs[i];

                if let Some(c) = (0..=n)
                    .filter(|i| cnts[*i][0] != 0)
                    .map(|i| ((rem + cnts[i][0] - 1) / cnts[i][0]) * costs[i])
                    .min()
                {
                    cost += c;
                } else {
                    break;
                }

                let rem = K.saturating_sub(
                    cnts[j][1]
                        + sc[i]
                            .0
                            .chars()
                            .rev()
                            .take_while(|&c| c != 'J')
                            .filter(|&c| c == 'O')
                            .count(),
                );
                cost += costs[j];
                if let Some(c) = (0..=n)
                    .filter(|&i| cnts[i][1] != 0)
                    .map(|i| ((rem + cnts[i][1] - 1) / cnts[i][1]) * costs[i])
                    .min()
                {
                    cost += c;
                } else {
                    break;
                }

                let rem = K.saturating_sub(
                    cnts[k][2]
                        + sc[j]
                            .0
                            .chars()
                            .rev()
                            .take_while(|&c| c != 'O')
                            .filter(|&c| c == 'I')
                            .count(),
                );
                cost += costs[k];
                if let Some(c) = (0..=n)
                    .filter(|&i| cnts[i][2] != 0)
                    .map(|i| ((rem + cnts[i][2] - 1) / cnts[i][2]) * costs[i])
                    .min()
                {
                    cost += c;
                } else {
                    break;
                }

                ans = ans.min(cost);
            }
        }
    }

    if ans == INF {
        println!("-1");
    } else {
        println!("{}", ans);
    }
}

const INF: usize = std::usize::MAX;

fn toidx(c: char) -> usize {
    match c {
        'J' => 0,
        'O' => 1,
        'I' => 2,
        _ => unreachable!(),
    }
}

mod input {
    #[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>>()
        };

        ($iter:expr, usize1) => {
            read_value!($iter, usize) - 1
        };

        ($iter:expr, $t:ty) => {
            $iter.next().unwrap().parse::<$t>().expect("Parse error")
        };
    }
}