#[allow(unused_imports)]
use std::cmp::*;
#[allow(unused_imports)]
use std::collections::*;
use std::io::{Write, BufWriter};
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

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

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, [ $t:tt ]) => {{
        let len = read_value!($next, usize);
        (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    }};

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

#[allow(unused)]
macro_rules! debug {
    ($($format:tt)*) => (write!(std::io::stderr(), $($format)*).unwrap());
}
#[allow(unused)]
macro_rules! debugln {
    ($($format:tt)*) => (writeln!(std::io::stderr(), $($format)*).unwrap());
}

macro_rules! chmin {
    ($x:expr,$y:expr) => {
        let val = min($x,$y);
        $x = val;
    }
}

fn solve() {
    let out = std::io::stdout();
    let mut out = BufWriter::new(out.lock());
    macro_rules! puts {
        ($($format:tt)*) => (let _ = write!(out,$($format)*););
    }
    input! {
        n: usize, v: usize, l: i64,
        xvw: [(i64, i64, i64); n],
    }
    let mut xvw = xvw;
    xvw.insert(0, (0, 0, 0));
    xvw.push((l, 0, 0));
    let n = xvw.len();
    const INF: i64 = 1 << 50;
    let mut dp = vec![vec![INF; v + 1]; n];
    dp[0][v] = 0;
    for i in 0..n - 1 {
        let (xi, _vi, _wi) = xvw[i];
        let (xn, vn, wn) = xvw[i + 1];
        for j in 0..v + 1 {
            if dp[i][j] >= INF { continue; }
            let to = j as i64 - xn + xi;
            if to < 0 { continue; }
            chmin!(dp[i + 1][to as usize], dp[i][j]);
            let to = min(v, (to + vn) as usize);
            chmin!(dp[i + 1][to], dp[i][j] + wn);
        }
    }
    let &mi = dp[n - 1].iter().min().unwrap();
    puts!("{}\n", if mi >= INF { -1 } else { mi });
}

fn main() {
    // In order to avoid potential stack overflow, spawn a new thread.
    let stack_size = 104_857_600; // 100 MB
    let thd = std::thread::Builder::new().stack_size(stack_size);
    thd.spawn(|| solve()).unwrap().join().unwrap();
}