import numpy as np

N, K = map(int, input().split())
INF = 10 ** 9
pizza = [tuple(map(int, input().split())) for _ in range(N)]
pizza.sort(key=lambda x: -x[0])

dp0 = np.zeros(K + 1, dtype=int)
dp1 = np.full(K + 1, -INF, dtype=int)
for p, d in pizza:
    new_dp0 = dp0.copy()
    new_dp1 = dp1.copy()
    new_dp1[p:] = np.maximum(new_dp1[p:], dp0[:-p] + d)
    new_dp0 = np.maximum(new_dp0, dp1 + d)
    dp0 = new_dp0
    dp1 = new_dp1
print(max(dp0.max(), dp1.max()))