#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
#define ls (now*2+1)
#define rs (now*2+2)
#define mid ((l+r)>>1)
const int mxn = 3e5+10;
ll N,L;
pll segtree[mxn*12];
pair<ll,pll> arr[mxn];
vector<pll> v;
vector<int> all;
void modify(int now,int l,int r,int s,int e,ll v){
if(l>=s&&e>=r){
segtree[now].sc += v;
return;
}
if(mid>=s)modify(now*2+1,l,mid,s,e,v);
if(mid<e)modify(now*2+2,mid+1,r,s,e,v);
segtree[now].fs = min(segtree[ls].fs+segtree[ls].sc,segtree[rs].fs+segtree[rs].sc);
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N>>L;
for(int i = 1;i<=N;i++){
cin>>arr[i].fs>>arr[i].sc.fs>>arr[i].sc.sc;
v.push_back(make_pair(arr[i].sc.sc,i));
all.push_back(arr[i].fs);
all.push_back(arr[i].fs+1);
if(arr[i].fs-1>0)all.push_back(arr[i].fs-1);
}
all.push_back(0);
all.push_back(L);
sort(all.begin(),all.end());
all.resize(unique(all.begin(),all.end())-all.begin());
while(all.back()>L)all.pop_back();
ll len = all.size();
for(int i = 0;i<len;i++){
modify(0,0,len,i,i,-all[i]);
}
ll ans = L;
sort(v.rbegin(),v.rend());
v.push_back(make_pair(0,0));
//for(auto &i:all)cout<<i<<',';cout<<endl;
for(int i = 0;i+1<v.size();i++){
int now = v[i].sc;
int p = lower_bound(all.begin(),all.end(),arr[now].fs)-all.begin();
modify(0,0,len,p+1,len,arr[now].sc.fs);
ll tans = max(-(segtree[0].fs+segtree[0].sc),v[i+1].fs);
//cout<<v[i].fs<<":"<<now<<","<<p<<" "<<tans<<endl;
if(v[i].fs>=tans)ans = min(ans,tans);
}
cout<<ans;
}
