let share our best childhood memories in these quarantine days.when i was small my favorite cartoon was doremon
i just want to share the doremon jingle

Jindagi sawar doon
ik nai bahaar doon
duniya hi badal doon mai to
pyara sa chamatkar hun
mai kisi ka sapna hun
jo aaj ban chuka hoon sach
ab ye mera sapna hai ki
sab ke sapne sach mai karoon
aasma ko choon loon
titli ban udun
(Han...helicopter)
An an an...
mai hun ik udta robo
doraemon
an an an
mai hun ik udta robo
doraemon

what is your best childhood memory

I have seen many times that last/second last question of div 3 is on trees like
- 627 f teached me about rerooting
- 629 e teached me prefix postfix number
- 624 e constructive algo on tree
and in many more div 3 i saw tree questions , so is that a coincidence or what

i am solving education 4 and landed on this question ,i tried but couldn't so i saw the editoria and i wrote code according to it , but i am getting runtime error in this code on tc 18 ,it says "Exit code is -1073741819" i dont know what it is ,can you please please help me debug. thanks a lot in advance.

very sorry for the bad written code.

after some modification i got ac but i still dont know why in this case was runtime error.