package net.ipipip0129.kotlin.yukicoder

import kotlin.math.max

fun main(args: Array<String>) {
    val num = readLine()!!.toInt()
    val numList = readLine()!!.split(" ").map { it.toInt() }
    val numMap = mutableMapOf<Int, Int>()
    var i = 0
    var ans = 0
    while (i < num) {
        if (numMap.containsKey(numList[i])) {
            ans = numMap.size
            i = numMap[numList[i]]!! + 1
            numMap.clear()
            numMap[numList[i]] = i
        } else {
            numMap[numList[i]] = i
        }
        i++
    }
    print(max(ans, numMap.size))
}