// https://yukicoder.me/problems/no/2862
fun main() {
    val n = readln().toInt()
    val s = readln().map { it - '0' }
    
    for (i in 0..<n - 2) {

        if (s[i] == 4) {
            if (s[i + 1] == 0) {
                if (s[i + 2] == 4) {
                    println("Found")
                    return

                }
            }
        }
    }
    println("NotFound")
}