N = int(input())
V = [input() for _ in range(N)]
S = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"

ans = []
for num in V:
    num = num.lstrip('0')
    d = []
    for n in num:
        d.append(S.index(n))
    m = max(d) + 1
    total = 0
    for i, v in enumerate(num, 1):
        total += S.index(v) * pow(m, len(num)-i)
    ans.append(total)

print(min(ans))