Problem:
Score : 100 points

Problem Statement

There are N items, numbered 1, 2, \ldots, N.
For each i (1 \leq i \leq N), Item i has a weight of w_i and a value of v_i.

Taro has decided to choose some of the N items and carry them home in a knapsack.
The capacity of the knapsack is W, which means that the sum of the weights of items taken must be at most W.

Find the maximum possible sum of the values of items that Taro takes home.

Constraints

All values in input are integers.

1 \leq N \leq 100

1 \leq W \leq 10^9

1 \leq w_i \leq W

1 \leq v_i \leq 10^3

Input

Input is given from Standard Input in the following format:

N W
w_1 v_1
w_2 v_2
:
w_N v_N

Output

Print the maximum possible sum of the values of items that Taro takes home.

Sample Input 1

3 8
3 30
4 50
5 60

Sample Output 1

90

Items 1 and 3 should be taken.
Then, the sum of the weights is 3 + 5 = 8, and the sum of the values is 30 + 60 = 90.

Sample Input 2

1 1000000000
1000000000 10

Sample Output 2

10

Sample Input 3

6 15
6 5
5 6
6 4
6 6
3 5
7 2

Sample Output 3

17

Items 2, 4 and 5 should be taken.
Then, the sum of the weights is 5 + 6 + 3 = 14, and the sum of the values is 6 + 6 + 5 = 17.

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <math.h>
#include <string.h>
#include <stack>
#include <map>
#include <unordered_map>
#include <climits>
using namespace std;
const int INF = 1e9;
#define ll long long
#define int ll
#define fast                      \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define testcase \
    int t;       \
    cin >> t;    \
    while (t--)
#define pb push_back
#define endl "\n"
#define deb1(x) cout << #x << ": " << x << endl
#define deb2(x, y) cout << #x << ": " << x << " | " << #y << ": " << y << endl
#define deb3(x, y, z) cout << #x << ": " << x << " | " << #y << ": " << y << " | " << #z << ": " << z << endl
#define deb4(x, y, z, w) cout << #x << ": " << x << " | " << #y << ": " << y << " | " << #z << ": " << z << " | " << #w << ": " << w << endl
#define deb5(a, b, c, d, e) cout << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << " | " << #d << ": " << d << " | " << #e << ": " << e << endl
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define sz(a) int((a).size())
#define pii pair<int, int>
#define fi first
#define se second
#define ld long double
#define vii vector<int>
#define all(v) v.begin(), v.end()
#define prec(n) fixed << setprecision(n)
const int MOD = (int)1e9 + 7;
const int MOD2 = 1007681537;
const ll LINF = (ll)1e18;
const ld PI = acos((ld)-1);
const ld EPS = 1e-12;
inline ll gcd(ll a, ll b)
{
    ll r;
    while (b)
    {
        r = a % b;
        a = b;
        b = r;
    }
    return a;
}
inline ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
inline ll fpow(ll n, ll k, int p = MOD)
{
    ll r = 1;
    for (; k; k >>= 1)
    {
        if (k & 1)
            r = r * n % p;
        n = n * n % p;
    }
    return r;
}
template <class T>
inline int chkmin(T &a, const T &val) { return val < a ? a = val, 1 : 0; }
template <class T>
inline int chkmax(T &a, const T &val) { return a < val ? a = val, 1 : 0; }
inline void addmod(int &a, int val, int p = MOD)
{
    if ((a = (a + val)) >= p)
        a -= p;
}
inline void submod(int &a, int val, int p = MOD)
{
    if ((a = (a - val)) < 0)
        a += p;
}
inline int mult(int a, int b, int p = MOD) { return (ll)a * b % p; }
inline int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
inline void get_arr(int arr[], int n)
{
    for (int i = 0; i < n; i++)
        cin >> arr[i];
}
inline void print_arr(int arr[], int n)
{
    for (int i = 0; i < n; i++)
        cout << arr[i] << " ";
    cout << endl;
}

int32_t main()
{
    int n,w;
    cin>>n>>w;
    int wt[n+1],arr[n+1];
    int v=0;
    for(int i=1;i<=n;i++)
    {
        cin>>wt[i];
        cin>>arr[i];
        v+=arr[i];
    }
    int dp[v+1];
    for(int i=0;i<=v;i++)
    {
        dp[i]=INF;
    }
    dp[0]=0;
    for(int i=1;i<=n;i++)
    {
        int a=wt[i];
        int b=arr[i];
        for(int j=v;j>=b;j--)
        {
            dp[j]=min(dp[j],dp[j-b]+a);
        }
    }
    for(int i=v;i>=0;i--)
    {
        if(dp[i]<=w)
        {
            cout<<i<<endl;
            break;
        }
    }
    // print_arr(dp,v+1);
}