#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define rep_up(i, a, n) for (ll i = a; i < n; ++i)
#define rep_down(i, a, n) for (ll i = a; i >= n; --i)
#define P pair<ll, ll>

#define all(v) v.begin(), v.end()
#define fi first
#define se second
#define vvvll vector<vector<vector<ll>>>
#define vvll vector<vector<ll>>
#define vll vector<ll>
#define pqll priority_queue<ll>
#define pqllg priority_queue<ll, vector<ll>, greater<ll>>

constexpr ll INF = (1ll << 60);
constexpr ll mod = 1000000007;
constexpr double pi = 3.14159265358979323846;
template <typename T>
inline bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <typename T>
inline bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return 1;
    }
    return 0;
}
ll mypow(ll a, ll n) {
    ll ret = 1;
    rep(i, n) {
        if (ret > (ll)(1e18 + 10) / a) return -1;
        ret *= a;
    }
    return ret;
}
long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}
int main(){
    ll n,a,p,x,ans=INF;
    cin>>n;
    rep(i,n){
        cin>>a>>p>>x;
        if(x-a>0) chmin(ans,p);
    }
    if(ans==INF) ans=-1;
    cout<<ans<<endl;
}

#include<bits/stdc++.h>
using namespace std;
int main(){
    long long A,B,C,D; cin >> A >> B >> C >> D;
    long long blue = A, red = 0;
    for(int i = 1; i <= A; i++){
        blue += B;
        red += C;
        if(blue <= D*red){
            cout << i << endl;
            return 0;
        }
    }
    cout << -1 << endl;
}