In many religions, there’s often a desire to marry within the faith. But what happens when your community is tiny and scattered around the world? That’s the problem facing young Zoroastrians. Zorastrians fled from Iran to India in the 10th century to escape religious persecution, but afterward, they migrated to other countries. So, for many of them who want to find a match within their religion, their best chance might be at this year's Zoroastrian Youth Congress in Los Angeles. The BBC's Nalini Sivathasan has one London woman's story.