Buggy python submission (verdict: Runtime Error):
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

using namespace std;
using ll = long long;

#define REP(i, a) for (int i = 0; i < (a); ++i)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORR(i, a, b) for (int i = (a)-1; i >= (b); --i)
#define ALL(obj) (obj).begin(), (obj).end()
#define SIZE(obj) (int)(obj).sizeT()
#define YESNO(cond, yes, no) \
    { cout << ((cond) ? (yes) : (no)) << endl; }
#define SORT(list) sort(ALL((list)));
#define RSORT(list) sort((list).rbegin(), (list).rend())
#define ASSERT(cond, mes) assert(cond&& mes)

constexpr int MOD = 1'000'000'007;
constexpr int INF = 1'050'000'000;

template <typename T>
T round_up(const T& a, const T& b) {
    return (a + (b - 1)) / b;
}

template <typename T1, typename T2>
istream& operator>>(istream& is, pair<T1, T2>& p) {
    is >> p.first >> p.second;
    return is;
}

template <typename T1, typename T2>
ostream& operator<<(ostream& os, pair<T1, T2>& p) {
    os << p.first << p.second;
    return os;
}

template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
    REP(i, (int)v.size())
    is >> v[i];
    return is;
}

template <typename T>
T clamp(T& n, T a, T b) {
    if (n < a) n = a;
    if (n > b) n = b;
    return n;
}

template <typename T>
static T GCD(T u, T v) {
    T r;
    while (v != 0) {
        r = u % v;
        u = v;
        v = r;
    }
    return u;
}

template <typename T>
static T LCM(T u, T v) {
    return u / GCD(u, v) * v;
}

template <typename T>
std::vector<T> enum_div(T n) {
    std::vector<T> ret;
    for (T i = 1; i * i <= n; ++i) {
        if (n % i == 0) {
            ret.push_back(i);
            if (i * i != n) { ret.push_back(n / i); }
        }
    }
    return ret;
}

template <typename T>
bool chmin(T& a, const T& b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template <typename T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

struct ToUpper {
    char operator()(char c) {
        return toupper(c);
    }
};

struct ToLower {
    char operator()(char c) {
        return tolower(c);
    }
};

int dp[41][401][401];

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);

    int N, Ma, Mb;
    cin >> N >> Ma >> Mb;
    vector<int> A(N), B(N), C(N);
    REP(i, N) {
        cin >> A[i] >> B[i] >> C[i];
    }
    vector<vector<vector<int>>> dp(
        41, vector<vector<int>>(401, vector<int>(401, INF)));
    dp[0][0][0] = 0;
    REP(i, N) {
        REP(j, 401) {
            REP(k, 401) {
                if (dp[i][j][k] == INF) continue;
                chmin(dp[i + 1][j][k], dp[i][j][k]);
                chmin(dp[i + 1][j + A[i]][k + B[i]], dp[i][j][k] + C[i]);
            }
        }
    }

    int ans = INF;
    FOR(i, 1, 401) {
        FOR(j, 1, 401) {
            if (dp[N][i][j] == INF) continue;
            if (Ma * j == Mb * i) { chmin(ans, dp[N][i][j]); }
        }
    }
    if (ans == INF) ans = -1;
    cout << ans << endl;
    return 0;
}


Fixed submission:
# -*- coding: utf-8 -*-
import sys
import math
import os
import itertools
import string
import heapq
import _collections
from collections import Counter
from collections import defaultdict
from functools import lru_cache
import bisect


class Scanner():
    @staticmethod
    def int():
        return int(sys.stdin.readline().rstrip())

    @staticmethod
    def string():
        return sys.stdin.readline().rstrip()

    @staticmethod
    def map_int():
        return [int(x) for x in Scanner.string().split()]

    @staticmethod
    def string_list(n):
        return [input() for i in range(n)]

    @staticmethod
    def int_list_list(n):
        return [Scanner.map_int() for i in range(n)]

    @staticmethod
    def int_cols_list(n):
        return [int(input()) for i in range(n)]


class Math():
    @staticmethod
    def gcd(a, b):
        if b == 0:
            return a
        return Math.gcd(b, a % b)

    @staticmethod
    def lcm(a, b):
        return (a * b) // Math.gcd(a, b)

    @staticmethod
    def roundUp(a, b):
        return -(-a // b)

    @staticmethod
    def toUpperMultiple(a, x):
        return Math.roundUp(a, x) * x

    @staticmethod
    def toLowerMultiple(a, x):
        return (a // x) * x

    @staticmethod
    def nearPow2(n):
        if n <= 0:
            return 0
        if n & (n - 1) == 0:
            return n
        ret = 1
        while(n > 0):
            ret <<= 1
            n >>= 1
        return ret

    @staticmethod
    def sign(n):
        if n == 0:
            return 0
        if n < 0:
            return -1
        return 1

    @staticmethod
    def isPrime(n):
        if n < 2:
            return False
        if n == 2:
            return True
        if n % 2 == 0:
            return False
        d = int(n ** 0.5) + 1
        for i in range(3, d + 1, 2):
            if n % i == 0:
                return False
        return True


MOD = int(1e09) + 7
INF = int(1e09)


def main():
    # sys.stdin = open("sample.txt")
    N, Ma, Mb = Scanner.map_int()
    A = [0] * N
    B = [0] * N
    C = [0] * N

    for i in range(N):
        a, b, c = Scanner.map_int()
        A[i], B[i], C[i] = a, b, c
    dp = [[[INF for _ in range(401)] for _ in range(401)] for _ in range(41)]
    dp[0][0][0] = 0
    for i in range(N):
        for j in range(401):
            for k in range(401):
                if dp[i][j][k] == INF:
                    continue
                dp[i+1][j][k] = min(dp[i+1][j][k], dp[i][j][k])
                dp[i+1][j + A[i]][k + B[i]] = min(
                    dp[i+1][j + A[i]][k + B[i]], dp[i][j][k] + C[i])

    ans = INF
    for i in range(1, 401):
        for j in range(1, 401):
            if dp[N][i][j] == INF:
                continue
            if Ma * j == Mb * i:
                ans = min(ans, dp[N][i][j])
    if ans == INF:
        ans = -1
    print(ans)


if __name__ == "__main__":
    main()