help=n/2;
while(help>0)
      i=0;
      while(i<n)
            {
             j=i-help;
             while(j>=0)
                   {
                    if(a[j]>a[j+help])
                       {
                        temp=a[j];
                        a[j]=a[j+help];
                        a[j+help]=temp;
                       }
                     j=j-help;
                    }
             i=i+1;
            }
     help=help/2;