n, k = map(int, input().split())
pizza = [ list(map(int, input().split())) for i in range(n) ]
pizza.sort()
pizza.reverse()
dp = [ [ -(1 << 26) ] * 2 for i in range(k + 1) ]
dp[0][0] = 0
for p, d in pizza:
    for i in range(k, -1, -1):
        dp[i][0] = max(dp[i][0], dp[i][1] + d)
        if i >= p:
            dp[i][1] = max(dp[i][1], dp[i - p][0] + d)

print(max([max(i) for i in dp]))