N, M = map(int, input().split())
items = []
for i in range(N):
    V, W = map(int, input().split())
    items.append((V, W))


def knapsack():
    dp = [-1] * (M+1)
    dp[0] = 0
    res = 0
    for v, w in sorted(items, reverse=True):
        for i in reversed(range(M)):
            if dp[i] == -1: continue
            if i+w > M: continue
            dp[i+w] = max(dp[i+w], dp[i] + v)

        res = max(res, v * max(dp))

    return res


ans = knapsack()
print(ans)