// tzl ak IOI! 

#include<bits/stdc++.h>

#define HEAP priority_queue
#define rep(i, n) for(int i = 0, _end_ = (n); i < _end_; ++i)
#define per(i, n) for(int i = (n) - 1; i >= 0 ; --i)
#define forn(i, l, r) for(int i = (l), _end_ = (r); i <= _end_; ++i)
#define nrof(i, r, l) for(int i = (r), _end_ = (l); i >= _end_; --i)
#define FOR(a, b) for(auto (a): (b))
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define X first
#define Y second
#define eps 1e-6
#define pi 3.1415926535897932384626433832795
#define SZ(x) (int)x.size()
#define ALL(x) x.begin(), x.end()
#define FILL(a, b) memset((a), (b), sizeof((a)))
#define MCPY(a, b) memcpy((a), (b), sizeof((b)))

using namespace std;

typedef long long LL;
typedef double flt;
typedef vector<int> vi;
typedef vector<LL> vl;
typedef pair<int,int> pii;
typedef pair<int,LL> pil;
typedef pair<LL,int> pli;
typedef pair<LL,LL> pll;
typedef vector<pil> vil;
typedef vector<pii> vii;
typedef vector<pli> vli;
typedef vector<pll> vll;

const int iinf = 1e9 + 7;
const LL linf = 1ll << 60;
const flt dinf = 1e60;

template <typename T>
inline void scf(T &x)
{
	bool f = 0; x = 0; char c = getchar();
	while((c < '0' || c > '9') && c != '-') c = getchar();
	if(c == '-') { f = 1; c = getchar(); }
	while(c >= '0' && c <= '9') { x = x * 10 + c - '0'; c = getchar(); }
	if(f) x = -x; return;
}

template <typename T1, typename T2>
void scf(T1 &x, T2 &y) { scf(x); return scf(y); }

template <typename T1, typename T2, typename T3>
void scf(T1 &x, T2 &y, T3 &z) { scf(x); scf(y); return scf(z); }

template <typename T1, typename T2, typename T3, typename T4>
void scf(T1 &x, T2 &y, T3 &z, T4 &w) { scf(x); scf(y); scf(z); return scf(w); }

inline char mygetchar(){ char c = getchar(); while(c == ' ' || c == '\n') c = getchar(); return c; }

template <typename T>
void chkmax(T &x, const T &y){ if(y > x) x = y; return; }

template <typename T>
void chkmin(T &x, const T &y){ if(y < x) x = y; return; }

#ifdef ONLINE_JUDGE
#define debug(x,c) ;
#else
#define DEBUG
#define debug(x,c) cerr<<#x<<"="<<x<<c;
#endif

void TZL();

void RANK1();

#define tzl int
#define ak main
#define IOI ()
tzl ak IOI
{
#undef tzl
#undef ak
#undef IOI

	TZL();
	RANK1();

#define tzl return
#define caisi 0
#define myy ;
	tzl caisi myy
#undef tzl
#undef caisi
#undef myy
}

//---------------------------head----------------------------

LL ans;
LL W, w1;
vl v[4], c[4];

void TZL()
{
	int n; scf(n);
	scf(W);
	scf(w1);
	LL x; scf(x);
	v[0].pb(x);
	forn(i, 1, n - 1)
	{
		LL ww, vv; scf(ww, vv);
		v[ww - w1].pb(vv);
	}
	rep(i, 4) sort(ALL(v[i])), reverse(ALL(v[i]));
	rep(i, 4) if(SZ(v[i]))
	{
		c[i].resize(SZ(v[i]));
		c[i][0] = v[i][0];
		forn(j, 1, SZ(v[i]) - 1) c[i][j] = c[i][j - 1] + v[i][j];
	}
	return;
}

void RANK1()
{
	forn(i0, 0, SZ(v[0])) forn(i1, 0, SZ(v[1])) forn(i2, 0, SZ(v[2]))
	{
		LL lft = W - (LL)i0 * w1 - (LL)i1 * (w1 + 1ll) - (LL)i2 * (w1 + 2ll);
		if(lft < 0) continue;
		LL cur = 0;
		if(i0) cur += c[0][i0 - 1];
		if(i1) cur += c[1][i1 - 1];
		if(i2) cur += c[2][i2 - 1];
		LL can_chs = lft / (w1 + 3ll);
		if(can_chs > SZ(c[3])) can_chs = SZ(c[3]);
		if(can_chs) cur += c[3][can_chs - 1];
		chkmax(ans, cur);
	}
	printf("%lld\n", ans);
	return;
}

Measured memory_bytes: 256