fun main() {
    val n = readLine()!!.toInt()
    val a = readLine()!!.split(" ").map { it.toLong() }

    if (a.any { it >= 4 }) {
        println(1_000_000_007)
        return
    }

    if (a.any { it == 0L }) {
        println(-1)
        return
    }

    var pi = 1L
    for (ai in a) {
        val k = (1..ai).fold(1) { acc, x -> (acc * x).toInt() }
        for (i in 0 until k) {
            pi *= ai
            if (pi > 1_000_000_007) {
                println(1_000_000_007)
                return
            }

        }
    }

    println(1_000_000_007 % pi)
}