here are my program:

var
  n,t,m,y,i,j,k:integer;
  a:array[1..1000] of integer;
  yes:boolean;

BEGIN
 readln(n,m,y);
 k:=0;
 yes:=false;
 for i:=0 to m-1 do
  begin
   t:=i;
   for j:=2 to n do t:=sqr(t) mod m;
   if t=y then begin yes:=true; inc(k); a[k]:=i; end;
  end;
 if not yes then writeln('-1')
 else
  begin
    for i:=1 to k-1 do write(a[i],' ');
    writeln(a[k]);
  end;
END.