#!/usr/bin/env python3

import sys
# import time
# import math
# import numpy as np
# import scipy.sparse.csgraph as cs            # csgraph_from_dense(ndarray, null_value=inf), bellman_ford(G, return_predecessors=True), dijkstra, floyd_warshall
# import random                                # random, uniform, randint, randrange, shuffle, sample
# import string                                # ascii_lowercase, ascii_uppercase, ascii_letters, digits, hexdigits
# import re                                    # re.compile(pattern) => ptn obj; p.search(s), p.match(s), p.finditer(s) => match obj; p.sub(after, s)
# from bisect import bisect_left, bisect_right # bisect_left(a, x, lo=0, hi=len(a)) returns i such that all(val<x for val in a[lo:i]) and all(val>-=x for val in a[i:hi]).
# from collections import deque                # deque class. deque(L): dq.append(x), dq.appendleft(x), dq.pop(), dq.popleft(), dq.rotate()
# from collections import defaultdict          # subclass of dict. defaultdict(facroty)
# from collections import Counter              # subclass of dict. Counter(iter): c.elements(), c.most_common(n), c.subtract(iter)
# from datetime import date, datetime          # date.today(), date(year,month,day) => date obj; datetime.now(), datetime(year,month,day,hour,second,microsecond) => datetime obj; subtraction => timedelta obj
# from datetime.datetime import strptime       # strptime('2019/01/01 10:05:20', '%Y/%m/%d/ %H:%M:%S') returns datetime obj
# from datetime import timedelta               # td.days, td.seconds, td.microseconds, td.total_seconds(). abs function is also available.
# from copy import copy, deepcopy              # use deepcopy to copy multi-dimentional matrix without reference
# from functools import reduce                 # reduce(f, iter[, init])
# from functools import lru_cache              # @lrucache ...arguments of functions should be able to be keys of dict (e.g. list is not allowed)
# from heapq import heapify, heappush, heappop # built-in list. heapify(L) changes list in-place to min-heap in O(n), heappush(heapL, x) and heappop(heapL) in O(lgn).
# from heapq import nlargest, nsmallest        # nlargest(n, iter[, key]) returns k-largest-list in O(n+klgn).
# from itertools import count, cycle, repeat   # count(start[,step]), cycle(iter), repeat(elm[,n])
# from itertools import groupby                # [(k, list(g)) for k, g in groupby('000112')] returns [('0',['0','0','0']), ('1',['1','1']), ('2',['2'])]
# from itertools import starmap                # starmap(pow, [[2,5], [3,2]]) returns [32, 9]
# from itertools import product, permutations  # product(iter, repeat=n), permutations(iter[,r])
# from itertools import combinations, combinations_with_replacement
from itertools import accumulate             # accumulate(iter[, f])
# from operator import itemgetter              # itemgetter(1), itemgetter('key')
# from fractions import gcd                    # for Python 3.4 (previous contest @AtCoder)



def main():
    mod = 1000000007                # 10^9+7
    inf = float('inf')              # sys.float_info.max = 1.79...e+308
    # inf = 2 ** 64 - 1             # (for fast JIT compile in PyPy) 1.84...e+19
    sys.setrecursionlimit(10**6)    # 1000 -> 1000000
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())
    
    n, w = mi()
    L = [lmi() for _ in range(n)]
    w1 = L[0][0]
    if n * (w1 + 3) <= w:
        print(sum(map(lambda x: x[1], L)))
    elif n * w <= 10**6:
        # 普通の dp 戦略
        dp = [0 for _ in range(w+1)]
        for i in range(n):
            weight, value = L[i]
            for j in range(w, 0, -1):
                if j - weight >= 0:
                    dp[j] = max(dp[j], dp[j - weight] + value)
        print(dp[w])
    else:
        group_by_weight = [[] for _ in range(4)]
        for weight, value in L:
            group_by_weight[weight - w1].append(value)
        w1_0 = sorted(group_by_weight[0], reverse=True)
        w1_1 = sorted(group_by_weight[1], reverse=True)
        w1_2 = sorted(group_by_weight[2], reverse=True)
        w1_3 = sorted(group_by_weight[3], reverse=True)
        accum_0, accum_1, accum_2, accum_3 = map(lambda x: [0] + list(accumulate(x)), [w1_0, w1_1, w1_2, w1_3])
        ans = -1
        for i in range(len(w1_0)+1):
            for j in range(len(w1_1)+1):
                for k in range(len(w1_2)+1):
                    for l in range(len(w1_3)+1):
                        if (i+j+k+l)*w1 + j + 2*k + 3*l <= w:
                            ans = max(ans, accum_0[i] + accum_1[j] + accum_2[k] + accum_3[l])
        print(ans)


if __name__ == "__main__":
    main()


Measured memory_bytes: 39792