let inputCount = Int(readLine()!)!

let numList = readLine()!.split(separator: " ").map{Int($0)!}.sorted()

var ans = 0
for i in 0..<numList.count {
    var isUnq = true
    if( i > 0 && numList[i-1] == numList[i]) {
        isUnq = false
    }
    if(i < numList.count-1 && numList[i] == numList[i+1]) {
        isUnq = false
    }
    if(isUnq) {
        ans+=1
    }
}

print(ans)