#include <iostream>
#include <iomanip>
#include <vector>
#include <list>
#include <deque>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <limits>

using namespace std;

#define REP(x,y) for(int x = 0;x < (y);x++)
#define LLI long long int
#define FORR(x,arr) for(auto& x:arr)
#define ALL(a) (a.begin()),(a.end())

#define _L(x) cout<<(x)<<endl

LLI dp[101010][2]; // pos, less

int N, L;
struct Data
{
    LLI X;
    LLI W;
    LLI T;
    
    LLI GetWait(LLI time) const
    {
        LLI sdiv = time / T;
        LLI ediv = (time+W) / T;
        LLI smod = time % T;
        LLI emod = (time+W) % T;
        if(sdiv % 2 == 1)
        {
            return T - smod;
        }
        if(ediv % 2 == 0)
        {
            return 0;
        }
        if(emod == 0)
        {
            return 0;
        }
        return 2 * T - smod;
    }
};

vector<Data> values;

int main()
{
    cin >> N >> L;
    values.resize(N);
    REP(i, N)
    {
        Data e;
        cin >> e.X >> e.W >> e.T;
        values[i] = e;
    }
    LLI currentTime = 0;
    LLI currentPosition = 0;
    REP(i, N)
    {
        currentTime += values[i].X - currentPosition;
        LLI wait =values[i].GetWait(currentTime);
        //cout << wait << endl;
        currentTime += wait;
        currentTime += values[i].W;
        currentPosition = values[i].X + values[i].W;
    }
    currentTime += L - currentPosition;
    cout << currentTime << endl;
}