MATHII  Yet Another Mathematical Problem
Calculate the number of ordered triples of positive integers (a, b, c) such that their multiple abc is not larger than a given integer N (1 <= N <= 10^{11}).
Input
Each test case contains a single line  N. Input terminates by EOF.
Output
For each test case output its case number (starting from 1) and the answer in a single line.
Example
Input: 1 3 6 10 15 21 28 Output: Case 1: 1 Case 2: 7 Case 3: 25 Case 4: 53 Case 5: 95 Case 6: 161 Case 7: 246
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[Lakshman]:
20180207 18:26:20
Never thought my heavily optimized with complexity more than $O(n^{2/3})) $ can get AC. Was this problem designed to get AC with complexity more than $O(n^{2/3})) $solution?


[Lakshman]:
20180113 15:39:47
Last edit: 20180207 18:26:32 

wellwet:
20140718 12:53:16
Precision problem with spoj' cbrt() is annoying... 

:D:
20121124 15:06:02
Yes, it seems that pretty big complexities like that are in the intended solutions range. 
Added by:  Fudan University Problem Setters 
Date:  20121121 
Time limit:  3s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  ACM/ICPC Regional Contest, Chengdu 2012 