N,I = map(int,input().split())

dp = [-1] * (I + 1)
dp[0] = 0

for _ in range(N):
    s,a = map(int,input().split())
    for j in range(I, -1, -1):
        if dp[j] == -1:
            continue
        if j + s > I:
            continue
        dp[j + s] = max(dp[j + s], dp[j] + a)
        
print(max(dp))