Linq - statement contains - CS1503 argument 1: cannot convert from 'int' to

Dear all.
This is my situation.

I have 2 very similar queries that only change for the condition.

They are a_query and b_query

Now I need a third c_query query where the records of
b_query are not present in a_query.

a_query = (from A in  t009_prog.Where(x => (x.d_prog_f <= dData)) /* <- Contition */
     join B in  t011_reg on A.id_prog equals B.id_prog
      join C in  t005_per on B.id_per equals C.id_per into AB
        from D in AB.DefaultIfEmpty()
          join C in  t021_com on D.id_per equals C.id_per

           orderby A.id_prog, C.id_per, B.id_reg descending, C.id_com

        select new UTILITY.cl_PRIVACY
          {
            id_prog = A.id_prog,
            id_reg = B.id_reg,
            id_per = C.id_per,
            id_com = C.id_com
           }).Distinct().ToList();




            
b_query = (from A in  t009_prog.Where(x => (x.d_prog_f > dData || x.d_prog_f == null)) /* <- Contition */
    join B in  t011_reg on A.id_prog equals B.id_prog
      join C in  t005_per on B.id_per equals C.id_per into AB
        from D in AB.DefaultIfEmpty()
            join C in  t021_com on D.id_per equals C.id_per

             orderby A.id_prog, C.id_per, B.id_reg descending, C.id_com

           select new UTILITY.cl_PRIVACY
            {
              id_prog = A.id_prog,
              id_reg = B.id_reg,
              id_per = C.id_per,
              id_com = C.id_com
             }).Distinct().ToList();



    public class cl_PRIVACY
    {
        public int id_prog { get; set; }
        public int id_reg { get; set; }
        public int id_per { get; set; }
        public int id_com { get; set; }
    }

For this aim I use "Contains" but I get the error message

Error CS1503 Argument 1: cannot convert from 'int' to 'UTILITY.cl_PRIVACY'

c_query = (from p in a_query

       where !b_query.Contains(p.id_per)

     select new UTILITY.cl_PRIVACY
        {
          id_prog = A.id_prog,
          id_reg = B.id_reg,
          id_per = C.id_per,
          id_com = C.id_com
         }).Distinct().ToList();