### BUGGY CODE ###

from __future__ import division, print_function

import os
import sys
from io import BytesIO, IOBase

if sys.version_info[0] < 3:
    from __builtin__ import xrange as range
    from future_builtins import ascii, filter, hex, map, oct, zip


def knapsack(W,n):
  if n==0 or W==0 :
    return 0
  elif cache.get((W,n)):
    return cache[(W,n)]
  
  else:
    if wt[n-1]<=W:
      cache[(W,n)]=max(knapsack(W,n-1),p[n-1]+knapsack(W-wt[n-1],n-1))
      return cache[(W,n)]
    else:
      cache[(W,n)]=knapsack(W,n-1)
      return cache[(W,n)]
    
wt,p=[],[]
cache={}
def main():
    n,w=map(int,input().split())
    
    for _ in range(n):
      temp_wt,temp_pr=map(int,input().split())
      wt.append(temp_wt)
      p.append(temp_pr)
    print(knapsack(w,n))

# region fastio

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", "\n"))
    if kwargs.pop("flush", False):
        file.flush()


if sys.version_info[0] < 3:
    sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
else:
    sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)

input = lambda: sys.stdin.readline().rstrip("\r\n")

# endregion

if __name__ == "__main__":
    main()

### FIXED CODE ###

n,W=map(int,input().split())
t = [[-1 for i in range(W + 1)] for j in range(n + 1)] 
  
  
def knapsack(wt, val, W, n):     
  
    # base conditions 
    if n == 0 or W == 0: 
        return 0
    if t[n][W] != -1: 
        return t[n][W] 
  
    # choice diagram code 
    if wt[n-1] <= W: 
        t[n][W] = max(val[n-1] + knapsack(wt, val, W-wt[n-1], n-1),knapsack(wt, val, W, n-1)) 
        return t[n][W] 
    elif wt[n-1] > W: 
        t[n][W] = knapsack(wt, val, W, n-1) 
        return t[n][W] 

weight,profit=[],[]
for _ in range(n):
  w,p=map(int,input().split())
  weight.append(w)
  profit.append(p) 
print(knapsack(weight,profit, W, n))