import strutils, sequtils, math, sets

proc `**`*(base: int, exp: int): int64 =
    var base: int64 = base.int64
    var exp:  int64 = exp.int64
    result = int64(1)
    while exp != 0:
        if (exp and 1) != 0:
            result *= base
        exp = exp shr 1
        base *= base

proc mypow64*(base: int, exp: int): int64 =
    var base: int64 = base.int64
    var exp:  int   = exp
    result = 1.int64
    for i in 0.. <exp:
        result *= base

proc mypow*(base: int, exp: int): int =
    var (base, exp) = (base, exp)
    result = 1
    for i in 0.. <exp:
        result *= base

###
const
    mydigits = toSeq('0'..'9') & toSeq('A'..'Z') #echo toSeq(Digits) (ΦωΦ)＜書けない！

var
    n = stdin.readLine.parseInt
    v = newSeq[string](n)
    lag :int64 = int64.high

for i in 0.. <n:
    v[i] = stdin.readLine

for line in v:
    var shinho = 0
    for c in line:
        var p = mydigits.find(c) + 1
        shinho = max(shinho, p)
    var tmp = int64(0)
    for i, c in line:
        var p = mydigits.find(c)
        tmp += mypow64(shinho, (line.len - i - 1)) * p
#        tmp += (shinho ** (line.len - i - 1)) * p # (ΦωΦ)＜無理！
    lag = min(lag, tmp)

echo lag