fn main() {
    let (n, v, c) = {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        let mut iter = line.split_whitespace();
        (
            iter.next().unwrap().parse::<usize>().unwrap(),
            iter.next().unwrap().parse::<usize>().unwrap(),
            iter.next().unwrap().parse::<usize>().unwrap(),
        )
    };
    let mut vw = Vec::new();
    for _ in 0..n {
        vw.push({
            let mut line = String::new();
            std::io::stdin().read_line(&mut line).unwrap();
            let mut iter = line.split_whitespace();
            (
                iter.next().unwrap().parse::<usize>().unwrap(),
                iter.next().unwrap().parse::<usize>().unwrap(),
            )
        });
    }

    let mut dp = vec![0; v + 1];

    for &(price, value) in vw.iter() {
        for i in (price..=v).rev() {
            dp[i] = dp[i].max(dp[i - price] + value + c);
        }
    }

    for &(price, value) in vw.iter() {
        for i in price..=v {
            dp[i] = dp[i].max(dp[i - price] + value);
        }
    }

    let ans = *dp.iter().max().unwrap();
    println!("{}", ans);
}