N,K=map(int,input().split())
pd=[]
dp=[[[-float("inf")]*2 for i in range(K+1)] for j in range(N+1)]
for i in range(N):
    pd.append(list(map(int,input().split())))
pd.sort(reverse=True)
dp[0][0][0]=0
for i in range(N):
    cost,value=pd[i]
    for j in range(K+1):
        dp[i+1][j][0]=max(dp[i][j][1]+value,dp[i][j][0],dp[i+1][j][0],dp[i][j][1])
        if cost+j<=K:
            dp[i+1][cost+j][1]=max(dp[i][j][0]+value,dp[i][j][1],dp[i+1][cost+j][1],dp[i][j][1]+value)
        dp[i+1][j][1]=max(dp[i][j][1],dp[i+1][j][1])
ans=-1
for i in range(1,K+1):
    ans=max(ans,dp[-1][i][0],dp[-1][i][1])
print(ans)