N,K = map(int, input().split())
L = [[int(l) for l in input().split()] for _ in range(N)]

L.sort(reverse=True)
dp = [[[0]*2 for _ in range(K+1)] for _ in range(N+1)]
for i in range(N):
    for j in range(K+1):
        if j < L[i][0] and dp[i][j][1] > 0:
            dp[i+1][j][0] = max(dp[i][j][0], dp[i][j][1]+L[i][1])
        elif j < L[i][0]:
            dp[i+1][j][0] = dp[i][j][0]
        else:
            if dp[i][j][1] > 0:
                dp[i+1][j][0] = max(dp[i][j][0], dp[i][j][1]+L[i][1])
            else:
                dp[i+1][j][0] = dp[i][j][0]
            dp[i+1][j][1] = max(dp[i][j][1], dp[i][j-L[i][0]][0]+L[i][1])

print(max(dp[N][K]))