import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); long ans = Long.MAX_VALUE; while (n-- > 0) { ArrayDeque stack = new ArrayDeque<>(); int max = 0; for (char c : sc.next().toCharArray()) { int v; if (c >= '0' && c <= '9') { v = c - '0'; } else { v = c - 'A' + 10; } max = Math.max(max, v); stack.push(v); } long tmp = 0; long base = 1; while (stack.size() > 0) { tmp += base * stack.pop(); base *= max + 1; } ans = Math.min(ans, tmp); } System.out.println(ans); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }