import kotlin.math.min

const val MOD = 1000000007L

fun main() {
    val a = readLine()!!.trim().toLong()
    var minScore = Long.MAX_VALUE
    for (n in 2 .. min(a, 1000000)) {
        var m = 0
        var s = a
        var r = 0L
        while (s > 0) {
            r += s % n
            s /= n
            ++m
        }
        if (r == 1L) {
            --m
        }
        minScore = min(minScore, m * n)
    }
    println(minScore)
}