fun main(args: Array<String>) {
    val n = readLine()!!.toInt()
    val ans = (1..n).map { convDec(readLine()!!) }.minOrNull()!!
    println(ans)
}

fun convDec(n:String):Long {
    val alpha = n.filter { it in 'A'..'Z' }
    var base = 10
    if(alpha.isEmpty()) {
        base = n.map { it.toString().toInt() }.maxOrNull()!! + 1
    } else {
        base = alpha.maxOrNull()!! - 'A' + 11
    }
    var mul = 1L
    var ans = 0L
    for(i in n.reversed()) {
        if(i in '0'..'9') {
            ans += (i-'0')*mul
        } else {
            ans += (i-'A'+10)*mul
        }
        mul*=base
    }
    return ans
}