0 difficult, in a way that tests your ability or determination: --
This has been a challenging time for us all.
1 difficult to deal with or achieve, especially in a way that forces you to prove your skill or determination to succeed: --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Можем да го завършим стъпка по стъпка, колкото и дълъг да е пътят и не може да бъде завършен, колкото и кратък да е пътят, ако дори не маркирате отпечатъка си.