override fun second(): Any? {

val prices = lines

.map { it.toLong() }

.map { number ->

val nums = generateSequence(number) { curr ->

val first = (curr xor (curr shl 6)) and modulo

val second = (first xor (first shr 5)) and modulo

val third = (second xor (second shl 11)) and modulo

third

}

.map { curr -> curr % 10 }

.take(2001)

.toList()

val diffs = nums.zipWithNext { a, b -> b - a }

val pairs = diffs.windowed(4).asReversed().zip(nums.asReversed()).reversed()

pairs.groupBy { it.first }.mapValues { it.value.first().second }

}

val allDiffs = prices.flatMap { currPrices -> currPrices.keys }.toSet()

return allDiffs.maxOf { diff ->

prices.sumOf { currPrices -> (currPrices[diff] ?: 0) }

}

}