2021 上海

#include<bits/stdc++.h>
#define TLE ios::sync_with_stdio(0),cin.tie(0)
#define endl "\n"
#define FILE "a"
#define pb push_back
#define gg exit(0);
#define rt return;
#define bd cout<<"debug"<<endl;
#define db(x) cout<<#x<<':'<<x<<endl;
#define dbb(i,a) cout<<#i<<':'<<i<<' '<<#a<<':'<<a<<' '<<endl;
#define dbbb(i,a,b) cout<<#i<<':'<<i<<' '<<#a<<':'<<a<<' '<<#b<<':'<<b<<endl;
#define TIME cout<<"RuningTime: "<<clock()<<"ms\n";
#define YES cout<<"YES"<<endl;
#define Yes cout<<"Yes"<<endl;
#define NO cout<<"NO"<<endl;
#define No cout<<"No"<<endl;
#define None cout<<-1<<endl;
#define el cout<<endl;
#define x first
#define y second
#define V vector
#define fo(i,j,n) for(int i = j;i<=n;i++)
#define of(i,n,j) for(int i = n;i>=j;i--)
#define fe(i,u) for(int i = h[u];~i;i=ne[i])
#define all(a) a.begin(),a.end()
#define alll(a) a.begin()+1,a.end()
#define ms(a,b) memset(a, b, sizeof(a));
#define tr_len(u) (tr[u].r - tr[u].l + 1)
#define tr_mid (tr[u].l + tr[u].r >> 1)
#define ul (u<<1)
#define ur (u<<1|1)
#define lowbit(x) (x&-x)
#define gcd(a,b) __gcd(a,b)
#define CLAP 11243
using namespace std;
void clapping() {
    #if CLAP == 1
    srand(time(NULL)+rand());
    freopen("a.in","r",stdin);
    freopen("a.out","w",stdout);
//    freopen("a.in","w",stdout);
    #endif
}
template<class T>inline void read(T &res) {
    char c;T flag = 1;
    while((c = getchar()) < '0' || c > '9') if(c == '-') flag = -1;res = c - '0';
    while((c=getchar())>='0'&&c<='9')res=(res<<1)+(res<<3)+(c^48);res*=flag;
}
typedef pair<int,int> pii;
typedef pair<long,long>pll;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3fll;
const double eps = 1e-8;
int dy[] = {1,0,-1,0,1,1,-1,-1};
int dx[] = {0,1,0,-1,1,-1,1,-1};
ll qmi(ll a,ll b) {int res = 1;for(;b;b>>=1,a = a * a ) {if(b&1) res = res * a;}return res;}
template<class T> T exgcd(T a,T b,T &x,T &y) {
    if(b == 0) {x = 1;y = 0;return a;}
    ll d = gcd_ed(b,a%b,y,x);
    y = y - a / b * x;
    return d;
}
template<class T> T qmul(T a,T b,T p) {
    T res = 0;
    for(;b;b >>= 1,a = (a + a) % p) {
        res = (res + a) % p;
    }
    return res;
}
/*文档区


*/
void AC()
{
    //
//                       _oo0oo_
//                      o8888888o
//                      88" . "88
//                      (| -_- |)
//                      0\  =  /0
//                    ___/`---'\___
//                  .' \\|     |// '.
//                 / \\|||  :  |||// \
//                / _||||| -:- |||||- \
//               |   | \\\  -  /// |   |
//               | \_|  ''\---/''  |_/ |
//               \  .-\__  '-'  ___/-. /
//             ___'. .'  /--.--\  `. .'___
//          ."" '<  `.___\_<|>_/___.' >' "".
//         | | :  `- \`.;`\ _ /`;.`/ - ` : | |
//         \  \ `_.   \_ __\ /__ _/   .-` /  /
//     =====`-.____`.___ \_____/___.-`___.-'=====
//                   佛祖保佑, 永无bug;
}


//-------------------------代码----------------------------

#define int ll
const int N = 2e5+10;
int n,m,k;

struct node {
    int p,v,t,id;
}p[N];

node q[N];

int l[N],r[N];

bool cmp1(node a,node b) {
    return a.id < b.id;
}

bool cmp2(node a,node b) {
    return a.p < b.p;
}

bool check(int t) {
    fo(i,1,n) {
        p[i].id = i;
        q[i] = p[i];
    }
    fo(i,1,n) {
        q[i].p = q[i].p + q[i].v * t;
    }
    sort(q+1,q+1+n,cmp2);
    for(int i = 1;i<=n;) {
        if(q[i].id == i) {
            i ++ ;
            continue;
        }
        int j = q[i].id;
        int idx = i + 1;
        while(idx <= n && idx <= j) {
            j = max(j,q[i].id);
            if(q[idx].t != q[i].t) return false;
            idx ++ ;
        }
        i = max(i+1,j);
    }
    
    
    return 1;
}

void solve()
{
//    cin>>n>>m;
    cin>>n>>k;
    fo(i,1,n) {
        int pp,v,t;cin>>pp>>v>>t;
        p[i] = {pp,v,t,i};
    }
    sort(p+1,p+1+n,cmp2);
    
    fo(i,1,n) {
        if(p[i].t == p[i-1].t) {
            l[i] = l[i-1];
        } else {
            l[i] = i;
        }
    }
    
    of(i,n,1) {
        if(p[i].t == p[i+1].t) {
            r[i] = r[i+1]
        }
    }
    
    
    
    
    
    int l = 1,r = 1e10;
    while(l < r) {
        int mid = l + r + 1>> 1;
        if(check(mid)) l = mid;
        else r = mid - 1;
    }
    if(l == 2e9 ) {
        cout<<-1<<endl;
    } else {
        cout<<l<<endl;
    }
}
void main_init() {}
signed main(){
    AC();clapping();TLE;
    cout<<fixed<<setprecision(12);
    main_init();
//  while(cin>>n,n)
//  while(cin>>n>>m,n,m)
//    int t;cin>>t;while(t -- )
    solve();
//    {solve(); }
    return 0;
}

/*样例区


*/

//------------------------------------------------------------