PLZ HELP!!! why?

#include<iostream>
using namespace std;
int main()
{
    int a,m,n;
    double d,o,w;

    cin>>n>>m;
    a=0;
    w=0;
    o=0;
    bool q=true;
    while(q){
        a++;
        d=m/(a << 1-1);
    if (w+d>=n){
        q=false;
    }
      w=w+d;
      o=o+m;
    }

  d=n-w;
  o=o+d*(a << 1-1);
  cout<<(abs(o+0.49999999999));
    return 0;
}

Edited by author 21.06.2014 02:18

Edited by author 21.06.2014 02:18

Edited by author 21.06.2014 21:29

Edited by author 21.06.2014 21:27