Could not find a part of the path

I am trying to write a pdf file to a hosted server  but I am getting the error below.

 This is the Code any ideas would be appreciated
FileStream f = new FileStream(@"\RecPDFs\Recs" + Session["InspectionIP"] + ".pdf", FileMode.Create);
 

m.WriteTo(f);

f.Close();

m.Close();

Could not find a part of the path 'c:\RecPDFs\Recs94.pdf'.
De ...