from tkinter import RIDGE


n, mx = map(int, input().split())
dp = [0] * (mx + 1)
for _ in range(n):
    s, a = map(int, input().split())
    for i in range(mx - s + 1)[::-1]:
        dp[i + s] = max(dp[i + s], dp[i] + a)
print(dp[mx])