import sys
input = sys.stdin.readline

N,W=map(int,input().split())

VW=[list(map(int,input().split())) for i in range(N)]

VW.sort(key=lambda x:x[0]/x[1],reverse=True)

DP=[0]*(10**7+1)

for v,w in VW:
    for i in range(10**7+1):
        if i+w<=10**7:
            DP[i+w]=max(DP[i+w],DP[i]+v)

if W<=10**7:
    print(DP[W])
else:
    v0,w0=VW[0]
    
    k=(W-10**7)//w0
    W1=W-(k+1)*w0
    V1=(k+1)*v0

    print(V1+DP[W1])