def main2(n,k,pd):
    from collections import defaultdict
    pd.sort(key=lambda x:x[0],reverse=True)
    dp0=defaultdict(lambda:-1)
    dp1=defaultdict(lambda:-1)
    dp0[0]=0
    for _,(p,d) in enumerate(pd):
        ndp0=defaultdict(lambda:-1)
        ndp1=defaultdict(lambda:-1)
        for i in dp0:
            # チケットなし
            if i+p<=k:
                ndp1[i+p]=max(ndp1[i+p],dp0[i]+d)
            ndp0[i]=max(ndp0[i],dp0[i])
        for i in dp1:
            # チケットあり
            ndp0[i]=max(ndp0[i],dp1[i]+d)
            ndp1[i]=max(ndp1[i],dp1[i])
        dp0=ndp0
        dp1=ndp1
    return max(max(dp0.values()),max(dp1.values()))

if __name__=='__main__':
    n,k=map(int,input().split())
    pd=[list(map(int,input().split())) for _ in range(n)]
    ret2=main2(n,k,pd)
    print(ret2)