for a := 1 to 13 do
for b := a to 13 do
for c := b to 13 do
for d := c to 13 do begin
v[1] := a; v[2] := b; v[3] := c; v[4] := d;
for idx := 1 to n do str(v[idx] : 0 : 0, expr[idx]);
hard := true; ans := '';
search(n, false);
if hard and (ans <> '') then begin
sum := sum + 1;
writeln(sum, ': ', ans);
end;
end;
end.