def s2m(s):
	ans = 36**12
	for n in range(2,37):
		tmp = 0
		for i,c in enumerate(s):
			z = int(c) if c.isdigit() else (ord(c)-55)
			if z >= n:
				break
			tmp += z*n**i
		else:
			ans = min(ans,tmp)
	return ans
N = input()
print min(s2m(raw_input()[::-1]) for i in range(N))