fun main(args: Array<String>) {
    val N = readLine()!!
    println(ushi(N))
}

inline fun ushi(N: String): Int {
    val len = N.length
    if (len <= 1 || N[0] != '1') return -1
    val i = N.count {it == '3'}
    return if (i == len - 1) i else -1
}