def main1(n,k,pd):
    pd.sort(key=lambda x:x[0],reverse=True)
    dp0=[-1]*(k+1)
    dp1=[-1]*(k+1)
    dp0[0]=0
    for p,d in pd:
        for i in range(k,-1,-1):
            if dp1[i]>=0:
                dp0[i]=max(dp0[i],dp1[i]+d)   # チケット使う
            if i-p>=0 and dp0[i-p]>=0:
                dp1[i]=max(dp1[i],dp0[i-p]+d) # 買う
    return max(max(dp0),max(dp1))
if __name__=='__main__':
    n,k=map(int,input().split())
    pd=[list(map(int,input().split())) for _ in range(n)]
    ret1=main1(n,k,pd)
    print(ret1)