USES crt;
VAR i:byte; s:integer;
Function kt(x:byte):boolean;
Var i:byte;
Begin
kt:=true;
if (x mod 2=0) or (x mod 3=0) then
begin
kt:=false;
exit;
end;
for i:=2 to trunc(sqrt(x)) do
if x mod i=0 then
begin
kt:=false;
exit;
end;
End;
BEGIN
clrscr;
writeln('Cac so nguyen to co 2 chu so gom:');
s:=0;
for i:=10 to 99 do
if kt(i) then
begin
write(i:4);
s:=s+i;
end;
readln;
END.