Problem 4; intermediate results, weeks 3+4

By 15th March 2020, there are 652 registered participants from 68 countries (the list of countries is given below). For the Problem 4, during the first week, 33 solutions were submitted, out of which 10 were correct. During the second week, 12 solutions were submitted, out of which 3 were correct. During the third week, 6 solutions were submitted, out of which 3 were correct. During the fourth week, 3 solutions were submitted, out of which 1 was correct.

Fourth week:

First NameSurnameSchool/UniversityCountryDateTime
PanFeiyueThe High School of Anhui Normal UniversityChina15/03/202009:37

Third week:

First NameSurnameSchool/UniversityCountryDateTime
RonaldDobošGymnázium, Poštová 9, KošiceSlovakia01/03/2016:42:00
BatuhanKeskinBogazici UniversityTurkey03/03/2018:15:00
Deng JianzhengShenzhen Senior High SchoolChina05/03/2005:20:00

Second week:

First NameSurnameSchool/UniversityCountryDateTime
YuechenZhuHenan Experimental High SchoolHenan Experimental High School24/02/2002:28:00
AntoniaGhitaInternational Computer High School of BucharestInternational Computer High School of Bucharest29/02/2020:43:00
Duc HuyTranThe Hong Kong University of Science and Technology (HKUST)The Hong Kong University of Science and Technology 01/03/2012:39:00

First week:

NameSurnameSchool/UniversityCountryDate time
ZhaoyanPangHarbin No.3 Senior HighChina16/02/2014:58:00
DobricaJovanovićMathematical Grammar School Serbia16/02/2015:34:00
TungLinhCurrently in gap yerVietnam16/02/2019:42:00
TevžLotričGimnazija KranjSlovenia16/02/2021:34:00
QuanNguyenHanoi-Amsterdam High School for the GiftedVietnam17/02/2014:18:00
JohanesSuhardjoHKUSTIndonesia18/02/2008:54:00
OliwierUrbańskiVII LO im. Dąbrówki w PoznaniuPoland18/02/2022:26:00
HanyiLiChengdu Foreign Languages SchoolChina19/02/2007:32:00
EndreBokorBudapesti Fazekas Mihály Gyakorló Általános Iskola és GimnáziumHungary22/02/2021:37:00
Fang TzuHsuNational Taiwan UniversityTaiwan23/02/2011:32:00

Participating countries: Australia, Azerbaijan, Bahrain, Bangladesh, Belarus , Bosnia and Herzegovina, Brasil, Bulgaria, Cambodia, Canada, China, Chinese Taipei, Costa Rica, Croatia, Ecuador, Egypt, El Salvador, Estonia, Finland, France, Georgia, Germany, Greece, Hong Kong, Hungary, India, Indonesia, Italy, Japan, Kazakhstan, Korea, Kosovo, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Macedonia (North), Malaysia, Mexico, Moldova, Mongolia, Morocco, Nepal, Netherlands, Nigeria, Pakistan, Peru, Philippines , Poland, Portugal, Romania, Russia, Saudi Arabia, Serbia, Singapore, Slovakia, Slovenia, Sweden, Switzerland, Syria, Tajikistan, Thailand, Turkey, Turkmenistan, United Kingdom, United States, Uzbekistan, Vietnam .