#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <tuple>
#include <bitset>
#include <map>
#include <set>
#include <queue>
#include <iomanip>

#define rep(i,n) for(i=0; i<n; ++i)
#define inc_rep(i,a,n) for(i=a; i<=n; ++i)
#define dec_rep(i,n,a) for(i=n; i>=a; --i)
#define in(a) cin >> a
#define out(a,b) cout << a << b
#define print_vec(v) for(auto it=v.begin();it!=v.end();++it)cout<<*it <<" ";cout<<endl
#define print_vec2d(v) for(int i=0;i<v.size();++i){for(int j=0;j<v[i].size();++j)cout<<v[i][j]<<" ";cout<<endl;}cout<<endl
#define print_vecpair(v) for(int i=0;i<v.size();++i)cout<<v[i].first<<" "<<v[i].second<<endl
#define vin(v) for(int i=0;i<v.size();++i)cin>>v[i]
#define vpairin(v) for(int i=0;i<v.size();++i){int a,b;cin>>a>>b;v[i]=make_pair(a,b);}
using namespace std;
using lint = long long;

int main(void){
    int i, j;
    lint k, cnt=0, x, y;
    lint p, q, n, m;
    string s;
    in(n);in(m);
    vector<pair<lint, lint> > v(n);
    vpairin(v);
    vector<vector<lint> > v2(n+1, vector<lint> (m+1));
    rep(i,n+1){
        rep(j,m+1){
            if(i==0||j==0) v2[i][j]=0;
            else{
                if(j-v[i-1].first>=0){
                    v2[i][j]=max(v2[i-1][j-v[i-1].first]+v[i-1].second, v2[i-1][j]);
                }
                else v2[i][j]=v2[i-1][j];
            }
        }
    }
    out(v2[n][m],endl);
    
    return 0;
}