1. 猜人数

program ex_1;
var
     i, f, t : integer;
begin
     f := 15;
     repeat
          if ((f-4) div 10) <> (f div 10) then
          begin
               t := trunc(sqrt(f));
               for i := 2 to t do
                   if (f mod i = 0) or ((f-4) mod i = 0) then
                      break;
               if (i = t) and (f mod i <> 0) and ((f-4) mod i <> 0) then
                     writeln(f+f-4, ' ' , f, ' ' , f-4);
          end;
          f := f+2;
     until f > 31;
     readln;
end.