from fractions import Fraction
N,W = list(map(int,input().split()))
item = []
for _ in range(N):
    v,w = list(map(int,input().split()))
    item.append((v,w))
item.sort(key=lambda x:Fraction(x[0],x[1]))

SIZE = 2*10**6
dp = [-1] * (SIZE+1)
dp[0] = 0
for i in range(N):
    v,w = item[i]
    for j in range(SIZE):
        if(j+w > SIZE):break
        dp[j+w] = max(dp[j+w], dp[j] + v)

if(W >= SIZE):
    v,w = item[-1]
    # W - w*x < SIZE
    # W - SIZE < w*x
    # (W - SIZE) / w < x

    x = -(-(W - SIZE)//w)
    print(max(dp[:W - w*x + 1]) + v*x)
else:
    print(max(dp[:W+1]))