pub use __cargo_equip::prelude::*;

use algebraic::{algebra, monoid};
use chminmax::chmax;
#[allow(unused_imports)]
use proconio::{
    input,
    marker::{Bytes, Chars, Usize1},
};
use sliding_window_aggregation::SlidingWindowAggregation;

algebra!(M, i64);
monoid!(M, -(1 << 60), |&a: &i64, &b: &i64| a.max(b));

fn main() {
    input! {
        n: usize,
        s: i64,
        h: i64,
    }
    let mut a = vec![-2_000_000_000];
    let mut b = vec![0];
    for _ in 0..n {
        input! {
            x: i64,
            y: i64,
            z: i64,
        }
        if y - x > s {
            continue;
        }
        a.push(x);
        a.push(y);
        b.push(0);
        b.push(z);
    }
    for i in 1..b.len() {
        b[i] += b[i - 1];
    }
    let mut dp1 = vec![0; a.len()]; // dp1[i]: 最後に寝始めたのがiのときの最大値

    // let mut dp2 = vec![0; a.len()]; // dp2[i]: 最後に起き上がったのがiのときの最大値
    let mut dq = SlidingWindowAggregation::<M>::new();
    let mut l1 = 0;
    let mut l2 = 0;
    let mut mx = -(1 << 60);
    for i in 0..a.len() {
        while l1 < a.len() && a[l1] + h <= a[i] {
            chmax!(mx, dp1[l1]);
            l1 += 1;
        }
        while l2 < a.len() && a[l2] + s < a[i] {
            dq.pop_front();
            l2 += 1;
        }
        chmax!(dp1[i], dq.prod() + b[i]);
        dq.push_back(mx - b[i]);
    }
    println!("{}", dp1.iter().max().unwrap());
}

// The following code was expanded by `cargo-equip`.

///  # Bundled libraries
/// 
///  - `path+file:///home/junji/code/cprs/crates/algebraic/algebraic#0.1.0`                       published in **missing** licensed under `CC0-1.0` as `crate::__cargo_equip::crates::algebraic`
///  - `path+file:///home/junji/code/cprs/crates/data-structure/sliding-window-aggregation#0.1.0` published in **missing** licensed under `CC0-1.0` as `crate::__cargo_equip::crates::sliding_window_aggregation`
///  - `path+file:///home/junji/code/cprs/crates/macros/chminmax#0.1.0`                           published in **missing** licensed under `CC0-1.0` as `crate::__cargo_equip::crates::chminmax`
#[cfg_attr(any(), rustfmt::skip)]
#[allow(unused)]
mod __cargo_equip {
    pub(crate) mod crates {
        pub mod algebraic {pub use crate::__cargo_equip::macros::algebraic::*;pub trait Algebra{type S;}pub trait Act:Algebra{type X;fn act(f:&Self::S,x:&Self::X)->Self::X;}pub trait Monoid:Algebra{fn e()->Self::S;fn op(x:&Self::S,y:&Self::S)->Self::S;}pub trait Group:Monoid{fn inv(x:&Self::S)->Self::S;}pub trait Zero{fn zero()->Self;fn is_zero(&self)->bool;}pub trait One{fn one()->Self;fn is_one(&self)->bool;}#[macro_export]macro_rules!__cargo_equip_macro_def_algebraic_algebra{($ident:ident,$ty:ty)=>{#[derive(Clone)]enum$ident{}impl$crate::__cargo_equip::crates::algebraic::Algebra for$ident{type S=$ty;}};}macro_rules!algebra{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_algebraic_algebra!{$($tt)*})}#[macro_export]macro_rules!__cargo_equip_macro_def_algebraic_act{($ident:ident,$tar:ty,$act:expr)=>{impl$crate::__cargo_equip::crates::algebraic::Act for$ident{type X=$tar;#[inline]fn act(f:&Self::S,x:&Self::X)->Self::X{$act(f,x)}}};}macro_rules!act{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_algebraic_act!{$($tt)*})}#[macro_export]macro_rules!__cargo_equip_macro_def_algebraic_monoid{($ident:ident,$e:expr,$op:expr)=>{impl$crate::__cargo_equip::crates::algebraic::Monoid for$ident{#[inline]fn e()->Self::S{$e}#[inline]fn op(x:&Self::S,y:&Self::S)->Self::S{$op(x,y)}}};}macro_rules!monoid{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_algebraic_monoid!{$($tt)*})}#[macro_export]macro_rules!__cargo_equip_macro_def_algebraic_group{($ident:ident,$e:expr,$op:expr,$inv:expr)=>{impl$crate::__cargo_equip::crates::algebraic::Monoid for$ident{#[inline]fn e()->Self::S{$e}#[inline]fn op(x:&Self::S,y:&Self::S)->Self::S{$op(x,y)}}impl$crate::__cargo_equip::crates::algebraic::Group for$ident{#[inline]fn inv(x:&Self::S)->Self::S{$inv(x)}}};}macro_rules!group{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_algebraic_group!{$($tt)*})}macro_rules!impl_zero_one{($($t:ty)*)=>{$(impl$crate::__cargo_equip::crates::algebraic::Zero for$t{fn zero()->Self{0}fn is_zero(&self)->bool{*self==0}}impl$crate::__cargo_equip::crates::algebraic::One for$t{fn one()->Self{1}fn is_one(&self)->bool{*self==1}})*};}impl_zero_one!(usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128);}
        pub mod sliding_window_aggregation {use crate::__cargo_equip::preludes::sliding_window_aggregation::*;use algebraic::Monoid;pub struct SlidingWindowAggregation<M>where M:Monoid,M::S:Clone,{fv:Vec<M::S>,bv:Vec<M::S>,fs:Vec<M::S>,bs:Vec<M::S>,}impl<M>SlidingWindowAggregation<M>where M:Monoid,M::S:Clone,{pub fn new()->Self{Self{fv:vec![],bv:vec![],fs:vec![M::e()],bs:vec![M::e()],}}pub fn clear(&mut self){self.fv.clear();self.bv.clear();self.fs.clear();self.fs.push(M::e());self.bs.clear();self.bs.push(M::e());}pub fn len(&self)->usize{self.fv.len()+self.bv.len()}pub fn is_empty(&self)->bool{self.len()==0}pub fn push_back(&mut self,x:M::S){self.bs.push(M::op(self.bs.last().unwrap(),&x));self.bv.push(x);}pub fn push_front(&mut self,x:M::S){self.fs.push(M::op(&x,self.fs.last().unwrap()));self.fv.push(x);}pub fn pop_back(&mut self)->Option<M::S>{if self.len()==0{None}else if self.len()==1{if self.bv.len()==1{self.bs.pop();self.bv.pop()}else{self.fs.pop();self.fv.pop()}}else{if self.bv.is_empty(){self.rebuild();}self.bs.pop();self.bv.pop()}}pub fn pop_front(&mut self)->Option<M::S>{if self.len()==0{None}else if self.len()==1{if self.bv.len()==1{self.bs.pop();self.bv.pop()}else{self.fs.pop();self.fv.pop()}}else{if self.fv.is_empty(){self.rebuild();}self.fs.pop();self.fv.pop()}}pub fn prod(&self)->M::S{M::op(self.fs.last().unwrap(),self.bs.last().unwrap())}fn rebuild(&mut self){let mut v=vec![];v.reserve(self.len());v.append(&mut self.fv);v.reverse();v.append(&mut self.bv);self.clear();for x in v[0..v.len()/2].iter().rev(){self.push_front(x.clone());}for x in&v[v.len()/2..v.len()]{self.push_back(x.clone());}}}}
        pub mod chminmax {pub use crate::__cargo_equip::macros::chminmax::*;#[macro_export]macro_rules!__cargo_equip_macro_def_chminmax_min{($a:expr$(,)*)=>{{$a}};($a:expr,$b:expr$(,)*)=>{{std::cmp::min($a,$b)}};($a:expr,$($rest:expr),+$(,)*)=>{{std::cmp::min($a,$crate::__cargo_equip::crates::chminmax::min!($($rest),+))}};}macro_rules!min{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_chminmax_min!{$($tt)*})}#[macro_export]macro_rules!__cargo_equip_macro_def_chminmax_max{($a:expr$(,)*)=>{{$a}};($a:expr,$b:expr$(,)*)=>{{std::cmp::max($a,$b)}};($a:expr,$($rest:expr),+$(,)*)=>{{std::cmp::max($a,$crate::__cargo_equip::crates::chminmax::max!($($rest),+))}};}macro_rules!max{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_chminmax_max!{$($tt)*})}#[macro_export]macro_rules!__cargo_equip_macro_def_chminmax_chmin{($base:expr,$($cmps:expr),+$(,)*)=>{{let cmp_min=$crate::__cargo_equip::crates::chminmax::min!($($cmps),+);if$base>cmp_min{$base=cmp_min;true}else{false}}};}macro_rules!chmin{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_chminmax_chmin!{$($tt)*})}#[macro_export]macro_rules!__cargo_equip_macro_def_chminmax_chmax{($base:expr,$($cmps:expr),+$(,)*)=>{{let cmp_max=$crate::__cargo_equip::crates::chminmax::max!($($cmps),+);if$base<cmp_max{$base=cmp_max;true}else{false}}};}macro_rules!chmax{($($tt:tt)*)=>(crate::__cargo_equip_macro_def_chminmax_chmax!{$($tt)*})}}
    }

    pub(crate) mod macros {
        pub mod algebraic {pub use crate::{__cargo_equip_macro_def_algebraic_act as act,__cargo_equip_macro_def_algebraic_algebra as algebra,__cargo_equip_macro_def_algebraic_group as group,__cargo_equip_macro_def_algebraic_monoid as monoid};}
        pub mod sliding_window_aggregation {}
        pub mod chminmax {pub use crate::{__cargo_equip_macro_def_chminmax_chmax as chmax,__cargo_equip_macro_def_chminmax_chmin as chmin,__cargo_equip_macro_def_chminmax_max as max,__cargo_equip_macro_def_chminmax_min as min};}
    }

    pub(crate) mod prelude {pub use crate::__cargo_equip::crates::*;}

    mod preludes {
        pub mod algebraic {}
        pub mod sliding_window_aggregation {pub(in crate::__cargo_equip)use crate::__cargo_equip::crates::algebraic;}
        pub mod chminmax {}
    }
}