import sys
#input = sys.stdin.readline
#input = sys.stdin.buffer.readline #文字列はダメ
#sys.setrecursionlimit(1000000)
import math
import bisect
#import itertools
#import random
from heapq import heapify, heappop, heappush
from collections import defaultdict 
#from collections import deque
import copy #DeepCopy: hoge = [_[:] for _ in hogehoge]
#from functools import lru_cache
#@lru_cache(maxsize=None)
MOD = pow(10,9) + 7
#MOD = 998244353
#dx = [1,0,-1,0]
#dy = [0,1,0,-1]
#dx8 = [1,1,0,-1,-1,-1,0,1]
#dy8 = [0,1,1,1,0,-1,-1,-1]

def main():
    N,I = map(int,input().split()); INF = 1 << 30
    S = [] ; A= []
    for i in range(N):
        s,a = map(int,input().split())
        S.append(s)
        A.append(a)

    # dp[i][j]:i番目の塩ラーメンまで見て塩の濃さがjの時の味の濃さの最大値
    M = 1005
    dp = [-INF]*M
    dp[0] = 0

    for s,a in zip(S,A):
        p = copy.copy(dp)
        dp,p = p,dp
        for j in range(M):
            if j+s < M:
                dp[j+s] = max(dp[j+s], p[j] + a)
        # print(dp[:20])

    ans = max(dp[:I+1])
    print(ans)


if __name__ == '__main__':
    main()