play different clips via GetKeyDown in unity

i have the Animator with parameters of bool type

 void Update()
     {
         if (Input.GetKeyDown(KeyCode.A))
         {
             anum.SetBool("ca", true);
           //  anum.SetBool("ca", false);
         }
         if (Input.GetKeyDown(KeyCode.S))
         {
             anum.SetBool("cv", true);
         } }

but only one first keydown is working.what 2 do?

UPD: I try with integer parameter,but it also doesnt work

  if (Input.GetKeyDown(KeyCode.A))
      {
          anum.SetInteger("letter", 1);   
          print("1111111111111111");
      }
 
      if (Input.GetKeyDown(KeyCode.S))
      {
          anum.SetInteger("letter", 2);
          print("22222222222222");     
      }