// ---------- begin Foldable Deque ----------
struct FoldableDeque<T, F> {
    front: Vec<(T, T)>,
    back: Vec<(T, T)>,
    op: F,
}

#[allow(dead_code)]
impl<T, F> FoldableDeque<T, F>
where T: Clone,
      F: Fn(&T, &T) -> T,
{
    fn new(op: F) -> Self {
        FoldableDeque {
            front: Vec::new(),
            back: Vec::new(),
            op: op,
        }
    }
    fn find(&self) -> Option<T> {
        match (self.front.last(), self.back.last()) {
            (Some(a), Some(b)) => Some((self.op)(&a.1, &b.1)),
            (Some(a), None) => Some(a.1.clone()),
            (None, Some(b)) => Some(b.1.clone()),
            (None, None) => None,
        }
    }
    fn clear(&mut self) {
        self.front.clear();
        self.back.clear();
    }
    fn len(&self) -> usize {
        self.front.len() + self.back.len()
    }
    fn push_back(&mut self, val: T) {
        let sum = if let Some(p) = self.back.last() {
            (self.op)(&p.1, &val)
        } else {
            val.clone()
        };
        self.back.push((val, sum));
    }
    fn push_front(&mut self, val: T) {
        let sum = if let Some(p) = self.front.last() {
            (self.op)(&val, &p.1)
        } else {
            val.clone()
        };
        self.front.push((val, sum));
    }
    fn pop_front(&mut self) -> Option<T> {
        if self.len() == 0 {
            return None;
        }
        if self.front.is_empty() {
            let a = self.back.clone();
            let m = (self.back.len() + 1) / 2;
            self.back.clear();
            let (f, b) = a.split_at(m);
            for v in f.iter().rev() {
                self.push_front(v.0.clone());
            }
            for v in b.iter() {
                self.push_back(v.0.clone());
            }
        }
        self.front.pop().map(|p| p.0)
    }
    fn pop_back(&mut self) -> Option<T> {
        if self.len() == 0 {
            return None;
        }
        if self.back.is_empty() {
            let a = self.front.clone();
            let m = self.front.len() / 2;
            self.front.clear();
            let (f, b) = a.split_at(m);
            for v in f.iter().rev() {
                self.push_front(v.0.clone());
            }
            for v in b.iter() {
                self.push_back(v.0.clone());
            }
        }
        self.back.pop().map(|p| p.0)
    }
}
// ---------- end Foldable Deque ----------
//https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 より
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

//

fn run() {
    input! {
        n: usize,
        v: usize,
        l: usize,
        p: [(usize, usize, u64); n],
    }
    let mut p = p;
    p.reverse();
    p.push((0, v, 0));
    p.reverse();
    p.push((l, v, 0));
    for p in p.iter_mut() {
        p.1 = std::cmp::min(p.1, v);
    }
    let inf = 1_000_000_000u64 * 2000 + 1;
    let mut dp = vec![0; v + 1];
    for p in p.windows(2) {
        let d = p[1].0 - p[0].0;
        if d > v {
            println!("-1");
            return;
        }
        let mut next = vec![inf; v + 1];
        for i in d..=v {
            next[i - d] = dp[i];
        }
        let (_, a, w) = p[1];
        let min = |a: &u64, b: &u64| std::cmp::min(*a, *b);
        let mut deq = FoldableDeque::new(min);
        let mut k = v + 1;
        for i in (a..=v).rev() {
            while k > 0 && i - (k - 1) <= a {
                k -= 1;
                deq.push_back(next[k]);
            }
            next[i] = std::cmp::min(next[i], next[i - a] + w);
            deq.pop_front();
        }
        dp = next;
    }
    let ans = dp.into_iter().min().unwrap();
    if ans >= inf {
        println!("-1");
    } else {
        println!("{}", ans);
    }
}

fn main() {
    run();
}