Truncatable primes

constant ltp = $[2, 3, 5, 7], -> @ltp {
    $[ grep { .&is-prime }, ((1..9) X~ @ltp) ]
} ... *;

constant rtp = $[2, 3, 5, 7], -> @rtp {
    $[ grep { .&is-prime }, (@rtp X~ (1..9)) ]
} ... *;

say "Highest ltp = ", ltp[5][*-1];
say "Highest rtp = ", rtp[5][*-1];

Output:

Highest ltp: 998443
Highest rtp: 739399