How should I treat my officemates with my first Salary

So I started working as an intern for a company I get an Allowance of Rs 30k per month so 31st January this month I will get my first paycheck from this company. So here there is a tradition where everyone who's working has to treat there colleagues something with there salary, (not with the whole salary), there are about 35 employees working in the office, so how should I treat them. Can you guys help me by giving me ideas.

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Update: after reading all your comments I have come to a conclusion that I'm gonna buy them cake. Chocolate cake at that 😋😋. Thankyou all for giving me suggestions. Nov gonna buy the cake from P&S though.