#include <bits/stdc++.h> #define FOR(i,a,b) for (int i=(a);i<(b);i++) #define FORR(i,a,b) for (int i=(a);i>=(b);i--) #define pb push_back #define pcnt __builtin_popcount #define show(x) cout<<#x<<" = "<<x<<endl; #define maxs(x,y) x = max(x,y) #define mins(x,y) x = min(x,y) #define fi first #define se second #define rng(a) a.begin(),a.end() #define each(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++) #define sz(x) (int)(x).size() #define mp make_pair using namespace std; typedef long long ll; typedef pair<int,int> pii; typedef vector<int> vi; typedef vector<vi> vvi; typedef vector<pii> vpii; typedef set<int> si; typedef pair<ll,ll> pll; typedef vector<ll> vl; typedef vector<vl> vvl; typedef vector<pll> vpll; typedef set<ll> sl; typedef __int128_t lll; typedef pair<lll,lll> plll; typedef vector<plll> vplll; template<typename T>string join(vector<T>&v) {stringstream s;FOR(i,0,sz(v))s<<' '<<v[i];return s.str().substr(1);} ll gcd(ll a,ll b){if(a>b)swap(a,b);for(;a>0;b%=a,swap(a,b));return b;} int modpow(ll a,ll n,int m){if(a==0)return a;ll p=1;for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;return(int)p;} void dout(double d){printf("%.12f\n",d);} const int iinf = 1e9; const ll linf = 1e18; const int mod = 1e9+7; const double pi = acos(-1); const double eps = 1e-10; ll n, w, sv, sw, ans; vpll x; int md, cnt, mcnt = 1000000; void search(int d){ if(cnt >= mcnt)return; if(d >= md){ cnt++; maxs(ans, sv); return; } if(w-sw>=x[d].se){ sw+=x[d].se; sv+=x[d].fi; search(d+1); sw-=x[d].se; sv-=x[d].fi; }else{ cnt++; maxs(ans, sv); } search(d+1); } main(){ cin.tie(0); ios::sync_with_stdio(false); cin >> n >> w; ll _v, _w; FOR(i, 0, n){ cin >> _v >> _w; if(_w > w) continue; x.pb(mp(_v, _w)); } sort(rng(x), [](pll&a, pll&b){return __int128_t(a.fi)*b.se < __int128_t(b.fi)*a.se;}); reverse(rng(x)); md=sz(x); search(0); cout << ans << endl; return 0; }