This is a classic case of working out how can you enjoy your 5 club tricks and also draw trumps.
The chance of trumps breaking 3-3 is around 35% and breaking 4-2 is around 48% (you won’t be able to cope with a 5-0 break).
So if you ruff the opening lead you will be reduced to 3 trumps in each hand.
Unless the trumps break 3-3 you will be defeated by the hand holding 4 trumps because they will force you in hearts.
The answer is quite simple.
Let the opposition lead 3 rounds of hearts while you discard 3 diamonds from hand.
You now can trump any 4th round of hearts in dummy whilst retaining your 4 trumps in hand. Any other lead allows you to win and draw trumps before enjoying your club suit.
THERE IS AN 80% CHANCE OF MAKING THIS CONTRACT PROVIDED YOU RECOGNISE THE DANGERS AND SEE THE SOLUTION AT TRICK ONE.