#![allow(unused_mut)]
#![allow(non_snake_case)]
#![allow(unused_macros)]
#![allow(unused_variables)]
#![allow(unused_imports)]
#![allow(dead_code)]
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($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 mut $var = read_value!($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:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

macro_rules! max {
    ($x: expr) => ($x);
    ($x: expr, $($y: expr),+) => {
        ::std::cmp::max($x, max!($($y),+))
    };
}

macro_rules! min {
    ($x: expr) => ($x);
    ($x: expr, $($y: expr),+) => {
        ::std::cmp::min($x, max!($($y),+))
    };
}

const MOD: usize = 1_000_000_007;
const MAX: usize = 510_000;
fn com_init(fac: &mut [usize], finv: &mut [usize], inv: &mut [usize]) {
    fac[0] = 1;
    fac[1] = 1;
    finv[0] = 1;
    finv[1] = 1;
    inv[1] = 1;
    for i in 2..MAX {
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }
}

fn bin_coef(n: usize, k: usize, fac: &mut [usize], finv: &mut [usize], inv: &mut [usize]) -> usize {
    if k > n/2 {
        bin_coef(n-k, k, fac, finv, inv)
    } else {
        fac[n] * (finv[k] * finv[n - k] % MOD) % MOD
    }
}


use std::cmp;
use std::collections::{HashSet, BinaryHeap, VecDeque, HashMap};
use std::iter::FromIterator;
fn main() {
    input!{
        N: usize,
        W: usize,
        budget: [(usize, usize); N],
    }

    let vmax = budget.iter().fold(0usize, |acc, &(_, v)| acc+v);
    let mut weights = vec![0; vmax+1]; 
    for &(w, v) in budget.iter() {
        for prev in (1..vmax+1-v).rev() {
            if weights[prev] > 0 && weights[prev+v] > 0 {
                weights[prev+v] = min!(weights[prev+v], weights[prev]+w);
            } else if weights[prev] > 0 {
                weights[prev+v] = weights[prev] + w;
            }
        }
        if weights[v] == 0 {
            weights[v] = w;
        } else {
            weights[v] = min!(weights[v], w)
        }
    }

    let (v, _) = weights.iter().enumerate().filter(|&(_, &w)| 0<w && w<=W).last().unwrap();
    println!("{}", v);
}

Measured memory_bytes: 4352