N, I = map(int, input().split())
dp = [0]*(I+1)

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