N,I=map(int,input().split())
dp=[-10**18]*1002
dp[0]=0
for i in range(N):
    s,a=map(int,input().split())
    for j in range(I+1,-1,-1):
        if j-s>=0:
            dp[j]=max(dp[j],dp[j-s]+a)

print(max(dp[:I+1]))