n, k = map(int, input().split())
info = [list(map(int, input().split())) for i in range(n)]
info = sorted(info, reverse = True)

dp = [[[0]*2 for _ in range(k+1)] for i in range(n+1)]

for i in range(n):
    cost, val = info[i]
    for j in range(k+1):
        # i番目を無料としてもらう
        if dp[i][j][1] != 0:
            dp[i+1][j][0] = max(dp[i][j][1] + val, dp[i+1][j][0])
        # i番目をお金を払ってもらう
        if j - cost >= 0:
            dp[i+1][j][1] = max(dp[i][j - cost][0] + val, dp[i+1][j][1])
        # i番目をもらわない
        dp[i+1][j][0] = max(dp[i][j][0], dp[i+1][j][0])
        dp[i+1][j][1] = max(dp[i][j][1], dp[i+1][j][1])

print(max(dp[n][k]))