Four rivers and three temples

Question

There are four river in such a way that they are like following -

River Temple River Temple River Temple River 

All the rivers are magical, moment a worshiper crosses a river with any number of flowers, it becomes double. (For eg 1 flower becomes 2 flowers, 2 become 4 and so on).

How many minimum number of flowers a worshiper needs to carry from beginning such that he offers equal number of flowers in all the three temples, and he is left with zero flowers at the end of fourth river.

Answer 1

7 Flowers

I came to this conclude with trail and error method.
I tried 1 flower as opening bal and he donates 1 flower, i came with answer 1 extra left instead of 0.

Then further trying i found the no of flowers he enters with and donates are same the output will also remain same.

But then i tried to have 1 flower more to be donate than no of he enters with.

With this i came to conclusion of minimum 7 flowers.

Answer 2

He must starts with 7 flowers and offers 8 flowers to 1 temple.