I was solve the 4177 "Tomato" problem. It shows it is a elementary problem. But, I think it is perfectly wrong.
Do you know why? The problem 4183 is also "Tomato". But, it has 4 directs. However, the problem 4177 "Tomato" has 6 directs. 4177 is elementary problem but it is harder than the high school problem 4183 "Tomato" I wish you confirm and make corrections quickly.