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

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

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

print(max(dp[0][n][k], dp[1][n][k]))