uva 10830 A New Function

/*
*   Author: johnsondu
*   time: 2013-4-25
*   problem: uva 10830 - A New Function
*   url: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1771
*   solution: http://www.algorithmist.com/index.php/UVa_10830
*       
*/

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <queue>
#include <cstring>
using namespace std ;

#define LL long long
#define inf 0xfffffff
#define M 1500005
#define N 200000
#define T 1005
#define max(x, y) (x > y ? x : y)
#define min(x, y) (x < y ? x : y)
LL n, num ;

LL solve ()
{
    LL ans = 0, lf, rt ;
    for (int i = 2; i*i <= n; i ++)
        ans += i * (n/i - 1) ;
    for (int i = 2; i * i < n; i ++)
    {
        lf = n / (i+1) + 1 ;
        rt = n / i ;
        if (lf > i)
            ans += (lf + rt) * (rt-lf+1) / 2 * (i-1) ;
    }
    return ans ;
}

int main ()
{
    int tcase, cs = 1 ;
    //freopen ("data.txt", "r", stdin) ;
    scanf ("%d", &tcase) ;
    while (tcase --)
    {
        scanf ("%lld", &n) ;
        printf ("Case %d: %lld\n", cs++, solve ()) ;

    }
    return 0 ;
}