iCloud subscriptions multiplied hundreds of times

My subscribed calendar for some reason multiplied in iCloud account and now I have more than 100 subscriptions there, which make Calendar application to consume 100% of CPU resources. How could I delete all subscribed calendars from my iCloud account?

Here's a screenshot: https://www.evernote.com/shard/s2/sh/4c659880-d410-4e42-bba4-36ebeac22a2d/61acd2 818526499b87b0e18edde8985a