N,K=map(int,input().split())
pd=[]
dp0,dp1=[[-float("inf")]*(K+1) for i in range(N+1)],[[-float("inf")]*(K+1) for i in range(N+1)]
dp0[0][0]=0
for i in range(N):
    pd.append(list(map(int,input().split())))
pd.sort(reverse=True)
for i in range(N):
    cost,value=pd[i]
    for j in range(K+1):
        dp0[i+1][j]=max(dp0[i][j],dp1[i][j]+value)
        dp1[i+1][j]=max(dp1[i][j],dp1[i+1][j])
        if cost+j<=K:
            dp1[i+1][j+cost]=max(dp0[i][j]+value,dp1[i][j]+value)
ans=-1
for i in range(1,K+1):
    ans=max(ans,dp0[-1][i],dp1[-1][i])
print(ans)