import sys

sys.setrecursionlimit(10 ** 6)
stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().strip()
ntp = lambda: tuple(map(int, stdin.readline().split()))
mod = 10 * 9 + 7
inf = 2 << 90

ans = ''
num = inf

n = ni()

for _ in range(n):
    S = list(ns())
    T = list(reversed(S))
    S.sort()
    m = 0

    if ord(S[-1]) > 57:
        j = ord(S[-1]) - 55
    else:
        j = int(S[-1])
    mx = j + 1

    for i in range(len(S)):
        if ord(T[i]) > 57:
            j = ord(T[i]) - 55
        else:
            j = int(T[i])
        m += j * (mx ** i)

    if m < num:
        num = m

print(num)