def _decimal_lshift_exact(n, e):
 if (n == 0):
  return 0
 elif (e >= 0):
  return (n * (10 ** e))
 else:
  str_n = str(abs(n))
  val_n = (len(str_n) - len(str_n.rstrip('0')))
  return (None if (val_n < (- e)) else (n // (10 ** (- e))))

def _decimal_lshift_exact ( n , e ) : if ( n == 0 ) : return 0 elif ( e >= 0 ) : return ( n * ( 10 ** e ) ) else : str_n = str ( abs ( n ) ) val_n = ( len ( str_n ) - len ( str_n . rstrip ( '0' ) ) ) return ( None if ( val_n < ( - e ) ) else ( n // ( 10 ** ( - e ) ) ) )
given integers n and e .