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

#define ll long long
#define ull unsigned long long
#define ld  long double

using LL = long long; using ULL = unsigned long long;
using VI = vector<int>; using VVI = vector<VI>; using VVVI = vector<VVI>;
using VL = vector<LL>; using VVL = vector<VL>; using VVVL = vector<VVL>;
using VB = vector<bool>; using VVB = vector<VB>; using VVVB = vector<VVB>;
using VD = vector<double>; using VVD = vector<VD>; using VVVD = vector<VVD>;
using VC = vector<char>; using VS = vector<string>; using VVC = vector<VC>;
using PII = pair<int,int>; using PLL = pair<LL,LL>; using PDD = pair<double,double>; using PIL = pair<int,LL>;
using MII = map<int,int>; using MLL = map<LL,LL>;
using SI = set<int>; using SL = set<LL>;
using MSI = multiset<int>; using MSL = multiset<LL>;
template<class T> using MAXPQ = priority_queue<T>;
template<class T> using MINPQ = priority_queue< T, vector<T>, greater<T> >;

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
#define PI  3.14159265358979323846

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define EACH(e, v) for(auto &e : v)
#define RITR(it, v) for(auto it = (v).rbegin(); it != (v).rend(); ++it)
#define ALL(v) v.begin(),v.end()

vector<ll> x8={1,1,1,0,0,-1,-1,-1},y8={1,0,-1,1,-1,1,0,-1};
int dx4[4]={1,-1,0,0}, dy4[4]={0,0,1,-1};

/*
memo
-uf,RMQ(segtree),BIT,BIT2,SegTree,SegTreeLazy
-isprime,Eratosthenes,gcdlcm,factorize,divisors,modpow,moddiv
nCr(+modnCr,inverse,extend_euclid.powmod),tobaseB,tobase10
-dijkstra,Floyd,bellmanford,sccd,topological,treediamiter
-compress1,compress2,rotate90

-co,ci,fo1,fo2,fo3,fo4
-bitsearch,binaryserach
-bfs
-SegTreedec,SegTreeLazydec
*/

template <typename X, typename M>
struct LazySegTree{
    using FX = function<X(X,X)>;
    using FA = function<X(M,X)>;
    using FM = function<M(M,M)>;

    long long n, N, log;
    vector<X> dat;
    vector<M> lazy;
    FX fx;
    FA fa;
    FM fm;
    X ex;
    M em;

    LazySegTree(long long _n, FX _fx, FA _fa, FM _fm, X _ex, M _em){
        init(_n,_fx,_fa,_fm,_ex,_em);
    }

    void init(long long _n, FX _fx, FA _fa, FM _fm, X _ex, M _em){
        N = _n, fx = _fx, fa = _fa, fm = _fm, ex = _ex, em = _em;
        long long x = 1;
        log = 0;
        while(_n > x) x *= 2, log++;
        n = x;
        dat.assign(n*2,ex);
        lazy.assign(n*2,em);
    }

    void pull_dat(long long k){
        dat[k] = fx(dat[2*k],dat[2*k+1]);
    }

    void apply_lazy(long long k, M f){
        dat[k] = fa(f, dat[k]);
        if(k < n) lazy[k] = fm(f, lazy[k]);
    }

    void push_lazy(long long k){
        if(lazy[k] == em) return;
        apply_lazy(2*k, lazy[k]);
        apply_lazy(2*k + 1, lazy[k]);
        lazy[k] = em;
    }

    void pull_dat_deep(long long k){
        for(int h = 1; h <= log; h++) pull_dat(k >> h);
    }

    void push_lazy_deep(long long k){
        for(int h = log; h >= 1; h--) push_lazy(k >> h);
    }

    //i番目の要素をxにアップデートする(0-indexed),O(logN)
    void set(long long i, X x){
        i += n;
        push_lazy_deep(i);
        dat[i] = x;
        pull_dat_deep(i);
    }

    //i番目の要素にアクセス(0-indexed),O(logN);
    X get(long long i){
        i += n;
        push_lazy_deep(i);
        return dat[i];
    }
    X operator[](long long i){return get(i);};

    //i番目の要素にfaを作用させる
    void apply(long long i, M f){
        i += n;
        push_lazy_deep(i);
        dat[i] = fa(f, dat[i]);
        pull_dat_deep(i);
    }

    //[l,r)までfaを作用させる
    void apply(long long l, long long r, M f){
        if(l == r) return;
        l += n, r += n;
        for(int h = log; h >= 1; h--){
            if(((l >> h) << h) != l) push_lazy(l >> h);
            if(((r >> h) << h) != r) push_lazy((r-1) >> h);
        }
        long long L = l, R = r;
        for(;l < r; l >>= 1, r >>= 1){
            if(l & 1) apply_lazy(l++,f);
            if(r & 1) apply_lazy(--r,f);
        }
        l = L, r = R;
        for(int h = 1; h <= log; h++){
            if(((l >> h) << h) != l) pull_dat(l >> h);
            if(((r >> h) << h) != r) pull_dat((r-1) >> h);
        }
    }
    //[l,r)で二項演算を作用した結果(0-indexed),O(logN)
    X prod(long long l, long long r){
        if(l == r) return ex;
        l += n, r += n;
        for(int h = log; h >= 1; h--){
            if(((l >> h) << h) != l) push_lazy(l >> h);
            if(((r >> h) << h) != r) push_lazy(r >> h);
        }
        X vleft = ex, vright = ex;
        for(; l < r; l >>= 1, r >>= 1){
            if(l & 1) vleft = fx(vleft,dat[l++]);
            if(r & 1) vright = fx(dat[--r],vright);
        }
        return fx(vleft,vright);
    }
    X all_prod(){return dat[1];};

    //x=prod(l,r),f(x)=trueとなる最大のrを求める(f(ex)=true, 0-indexed),O(logN)
    long long max_right(function<bool(X)> f, long long l = 0){
        if(l == N) return N;
        l += n;
        push_lazy_deep(l);
        X sum = ex;
        do{
            while(l % 2 == 0) l >>= 1;
            if(!f(fx(sum,dat[l]))){
                while(l < n){
                    push_lazy(l);
                    l *= 2;
                    if(f(fx(sum,dat[l]))){
                        sum = fx(sum,dat[l]);
                        l++;
                    }
                }
                return l - n;
            }
            sum = fx(sum,dat[l]);
            l++;
        }while((l & -l) != l);
        return N;
    }

    //x=prod(l,r),f(x)=trueとなる最小のlを求める(f(ex)=true, 0-indexed),O(logN)
    long long min_left(function<bool(X)> f, long long r = -1){
        if(r == 0) return 0;
        if(r == -1) return N;
        r += n;
        push_lazy_deep(r-1);
        X sum = ex;
        do{
            r--;
            while(r > 1 && (r % 2)) r >>= 1;
            if(!f(fx(dat[r],sum))){
                while(r < n){
                    push_lazy(r);
                    r *= 2;
                    if(f(fx(dat[r],sum))){
                        sum = fx(dat[r],sum);
                        r--;
                    }
                }
                return r + 1 - n;
            }
            sum = fx(dat[r],sum);
        }while((r & -r) != r);
        return 0;
    }
};

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(0);
    ll N,T; cin >> N >> T;
    VL l(N),r(N),p(N);
    for(ll i = 0; i < N; i++) cin >> l[i] >> r[i] >> p[i];

    vector<PLL> h;
    for(ll i = 0; i < N; i++) h.push_back({p[i],i});
    sort(ALL(h));

    ll K = 2e5;
    using X = ll;
    using M = ll;
    auto fx = [](X x1, X x2){return min(x1,x2);};
    X ex = -1;
    M em = -INF;
    auto fa = [](M m, X x){return (m != -INF? m : x);};
    auto fm = [](M m1, M m2){return (m1 != -INF? m1 : m2 );};
    LazySegTree<X,M> point(K+1,fx,fa,fm,ex,em);

    for(ll i = 0; i < N; i++){
        auto [P,id] = h[i];
        ll L = l[id],R = r[id];
        point.apply(L,R+1,P);
    }

    VL dp(K+2,0);
    for(ll i = 0; i <= K; i++){
        ll P = point[i];
        ll nxt = min(K+1,i+T);
        dp[i+1] = max(dp[i+1],dp[i]);
        dp[nxt] = max(dp[nxt],dp[i]+P);
    }

    cout << dp[K+1] << '\n';
    
    
}