i got wa on 16 please give me test# 16, i don't know where my mistake: size of heap and arrays are enough.

I get WA 16 too. =)

I don't know your mistake, but my mistake is ... I use "short". Never use "short"! Use "long" or "__int64". =)

Max. count of "boots changes" == 500*500 > 32000. It's funny. =)