No Error Streak II
250 XP
Make no error for 20 problems.
20/20
Common
Recently completed by
Joffrey Lebon 7k, 
Theo van Hintum 6k, 
Krin Krinchai 5k, 
Pier Camillo Iovino 10k, 
qqrooza 8k, 
Алексей Лестаров 10k
and 9302 others.
