> > #include <iostream.h>
> > #include <math.h>
> > void main()
> > {   float k;
> >     long i,l;
> > cin>>k;
> > {l=int(k)-1;
> > for(i=2;i<=sqrt(k)+4;i++) if ((k/i==int(k/i))&& (i>=3) ){l=i-
> > 1;break;};
#include<iostream.h>
#include<math.h>
int k,l;
void main()
{
    cin>>k;
    long temp=(long)floor(sqrt(k))+2;//be care about k=4
    for(long i=3;i<=temp;i++)
        if(k%i==0){
            cout<<i-1;
            return;
        }

    if(k%2==0)k/=2;
    cout<<k-1;

}
> > cout<<l;};
> > }
> Though I don't know what wrong about
> sqrt(k)+4 but
> I use k/2 instead of sqrt(k) and Get a AC
> try it please .
> I haven't learn C++ but I learned C and Pascal
> Why don't you use % in you program?
> If there is no % in C++ you can try this
> (k/i-int(k/i)<1e-15)
> and i think you'll get AC then.
> At last I give you a AC C program;
> #include<math.h>
> void main()
> {
>   long n;
>   long i;
>   scanf("%ld",&n);
>   for (i=3;i<=n/2;i++)
>     if (!(n%i))
>       {printf("%ld\n",i-1);exit();}
>   printf("%ld\n",n-1);
> }
> Good luck next time.:-)
>