#![allow(unused_imports, unused_macros, dead_code)]

macro_rules! min {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| min!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = min!($($ys),*);
        if $x < t { $x } else { t }
    }}
}
macro_rules! max {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| max!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = max!($($ys),*);
        if $x > t { $x } else { t }
    }}
}
macro_rules! ewriteln {
    ($($args:expr),*) => { let _ = writeln!(&mut std::io::stderr(), $($args),*); };
}
macro_rules! trace {
    ($x:expr) => { ewriteln!(">>> {} = {:?}", stringify!($x), $x) };
    ($($xs:expr),*) => { trace!(($($xs),*)) }
}
macro_rules! put {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        if let Some(x) = it.next() { print!("{}", x); }
        for x in it { print!(" {}", x); }
        println!("");
    }};
    ($x:expr) => { println!("{}", $x) };
    ($x:expr, $($xs:expr),*) => { print!("{} ", $x); put!($($xs),*) }
}

const M: i64 = 1_000_000_007;
trait Group: std::ops::Add<Output=Self> + std::ops::Sub<Output=Self> + std::ops::Neg<Output=Self>
    + std::iter::Sum + Clone + Copy {
    fn zero() -> Self;
}
impl Group for i32 { fn zero() -> Self { 0 }}
impl Group for i64 { fn zero() -> Self { 0 }}
impl Group for f32 { fn zero() -> Self { 0.0 }}
impl Group for f64 { fn zero() -> Self { 0.0 }}

trait Ring: Group + std::ops::Mul<Output=Self> + std::ops::Div<Output=Self> {
    fn one() -> Self;
}
impl Ring for i32 { fn one() -> Self { 1 }}
impl Ring for i64 { fn one() -> Self { 1 }}
impl Ring for f32 { fn one() -> Self { 1.0 }}
impl Ring for f64 { fn one() -> Self { 1.0 }}

#[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Debug)]
enum Hyper<X> { NegInf, Real(X), Inf }
use Hyper::{Real, NegInf, Inf};
impl<X: Ring> std::ops::Add for Hyper<X> {
    type Output = Self;
    fn add(self, rhs: Hyper<X>) -> Hyper<X> {
        match (self, rhs) {
            (Real(x), Real(y)) => Real(x + y),
            (Inf, _) => Inf,
            (_, Inf) => Inf,
            _ => NegInf,
        }
    }
}
impl<X: Ring> std::ops::Sub for Hyper<X> {
    type Output = Self;
    fn sub(self, rhs: Hyper<X>) -> Hyper<X> {
        self + (-rhs)
    }
}
impl<X: Ring> std::ops::Neg for Hyper<X> {
    type Output = Self;
    fn neg(self) -> Hyper<X> {
        match self {
            Inf => NegInf,
            NegInf => Inf,
            Real(x) => Real(-x),
        }
    }
}

fn main() {
    let mut sc = Scanner::new();
    let n: usize = sc.cin();
    let ma: usize = sc.cin();
    let mb: usize = sc.cin();

    let size = 500;
    let mut memo: Vec<Vec<Hyper<usize>>> = vec![vec![Inf; size]; size];
    memo[0][0] = Real(0);

    for _ in 0..n {
        let a: usize = sc.cin();
        let b: usize = sc.cin();
        let c: usize = sc.cin();
        for i in (0..size).rev() {
            for j in (0..size).rev() {
                if let Real(z) = memo[i][j] {
                    if i + a < size && j + b < size {
                        memo[i + a][j + b] = min!(memo[i + a][j + b], Hyper::Real(z + c));
                    }
                }
            }
            // trace!(i, &memo[i]);
        }
    }

    let mut ans = Inf;

    for i in 0..size {
        for j in 0..size {
            if i == 0 && j == 0 { continue }
            if i * mb == j * ma {
                ans = min!(ans, memo[i][j]);
            }
        }
    }

    if let Real(a) = ans {
        put!(a);
    } else {
        put!(-1);
    }

}

use std::io::{self, Write};
use std::str::FromStr;
use std::collections::VecDeque;

struct Scanner { stdin: io::Stdin, buffer: VecDeque<String>, }
impl Scanner {
    fn new() -> Self { Scanner { stdin: io::stdin(), buffer: VecDeque::new() } }
    fn cin<T: FromStr>(&mut self) -> T {
        while self.buffer.len() == 0 {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
        self.buffer.pop_front().unwrap().parse::<T>().ok().unwrap()
    }
    fn chars(&mut self) -> Vec<char> { self.cin::<String>().chars().collect() }
    fn vec<T: FromStr>(&mut self, n: usize) -> Vec<T> { (0..n).map(|_| self.cin()).collect() }
}


Measured memory_bytes: 8444