from math import gcd
from functools import cmp_to_key

class Fraction:
    def __init__(self, top, bottom):
        self.top = top
        self.bottom = bottom

def to_fraction(n):
    if type(n) == int:
        return Fraction(n, 1)
    else:
        return n

def compare(L, R):
    L, R = to_fraction(L), to_fraction(R)
    a = L.top*R.bottom
    b = L.bottom*R.top
    if a < b:
        return -1
    elif a == b:
        return 0
    else:
        return 1
    
def max_f(L, R):
    return L if compare(L, R) == 1 else R

def min_f(L, R):
    return L if compare(L, R) == -1 else R

def ADD(L, R):
    L, R = to_fraction(L), to_fraction(R)
    l, r = L.bottom, R.bottom
    lt = L.top*r
    rt = R.top*l
    top = lt+rt
    bottom = l*r
    GCD = gcd(top, bottom)
    top //= GCD
    bottom //= GCD
    return Fraction(top, bottom)

def SUB(L, R):
    L, R = to_fraction(L), to_fraction(R)
    l, r = L.bottom, R.bottom
    lt = L.top*r
    rt = R.top*l
    top = lt-rt
    bottom = l*r
    GCD = gcd(top, bottom)
    top //= GCD
    bottom //= GCD
    return Fraction(top, bottom)

def MUL(L, R):
    L, R = to_fraction(L), to_fraction(R)
    top = L.top*R.top
    bottom = L.bottom*R.bottom
    GCD = gcd(top, bottom)
    top //= GCD
    bottom //= GCD
    return Fraction(top, bottom)

def DIV(L, R):
    L, R = to_fraction(L), to_fraction(R)
    top = L.top*R.bottom
    bottom = L.bottom*R.top
    GCD = gcd(top, bottom)
    top //= GCD
    bottom //= GCD
    return Fraction(top, bottom)

INF = 1<<60

N, W = map(int, input().split())
item = [list(map(int, input().split())) for _ in range(N)]

L = 10**6*2
dp = [-INF]*(L+1)
dp[0] = 0
for v, w in item:
    for i in range(L+1):
        if dp[i] == -INF:
            continue
        if i+w <= L:
            dp[i+w] = max(dp[i+w], dp[i]+v)

ans = 0
if L < W:
    cm = cmp_to_key(compare)
    for i in range(N):
        item[i] = Fraction(*item[i])
    item.sort(key=cm, reverse=True)
    v, w = item[0].top, item[0].bottom

    diff = W-L
    cnt = (diff+w-1)//w
    ans = v*cnt
    W -= w*cnt

print(ans+max(dp[:W+1]))