`\color{red}{\text{@hoangduy67}}`

#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){

ios_base::sync_with_stdio(0);

cin.tie(0); cout.tie(0);
int n, w; cin >> n >> w;

vector <pair<int, int>> a(n);

for (auto &x: a) cin >> x.first >> x.second;

int ans = 0;

for (int mask = 1; mask < (1 << n); mask++){

int value = 0, weight = 0;

for (int i = 0; i < n; i++)

if (mask >> i & 1){

weight += a[i].first;

value += a[i].second;

}

if (weight <= w) ans = max(ans, value);

}

cout << ans;

return 0^0;

}

uses crt;
var  a,b:array[0..200] of longint;
     i,j,n: integer;  f: text;
     L,D: array[0..1000,0..1000] of longint;
     kt:array[0..200] of boolean;
     X: array[0..200] of int64;
     max,w,h,k:int64;
procedure inp;
 begin
      readln(n,k);
      for i:=1 to n do readln(a[i],b[i]);
 end;

procedure try(j:integer);
 var i:integer;
 begin
 for i:=X[j-1]+1 to n do
   if kt[i] and (w+a[i]<=K) then
    begin
     X[j]:=i; kt[i]:=false;
     w:=w+a[i];
     h:=h+b[i];
     if max<h then max:=h;
     if j<=n then try(j+1);
     w:=w-a[i];
     h:=h-b[i];
     kt[i]:=true;
    end;
 end;
 procedure duyet;
  begin
   for i:=1 to n do kt[i]:=true;
   w:=0; h:=0; max:=0;
   try(1);
  end;

 procedure otp;
 begin
     writeln(max);
 end;
procedure pro;
 begin
      for i:=0 to n do
        for j:=0 to k do l[i,j]:=0;
      for j:=0 to k do
       for i:=1 to n do
         begin  l[i,j]:=l[i-1,j];
              if (a[i]<=j) and (l[i,j]<=b[i]+l[i-1,j-a[i]]) then l[i,j]:=b[i]+l[i-1,j-a[i]];
         end;
      max:=l[n,k];
 end;
Begin
     inp;
     if n<100 then duyet else  pro;
     otp;
     readln
End.