![[old] Unlucky Days](https://dk1vwk12q8pjl.cloudfront.net/media/logos/task/middle/fiday-disabled_m6MIyOl.png)
[old] Unlucky Days
Friday 13th or Black Friday is considered as unlucky day. Calculate how many unlucky days are in...
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Friday 13th or Black Friday is considered as unlucky day. Calculate how many unlucky days are in...