import java.util.*;

public class Main {
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	long min = Long.MAX_VALUE;
    	for (int i = 0; i < n; i++) {
    	    min = Math.min(min, getValue(sc.next().toCharArray()));
    	}
    	System.out.print(min);
	}

	static long getValue(char[] arr) {
	    char max = '0';
	    for (char c : arr) {
	        max = (char)Math.max(max, c);
	    }
	    int idxed = 0;
	    if (max >= 'A') {
	        idxed = 10 + max - 'A';
	    } else {
	        idxed = max - '0';
	    }
	    idxed++;
	    long value = 0;
	    for (char c : arr) {
	        value *= idxed;
	        if (c >= 'A') {
	            value += 10 + c - 'A';
	        } else {
	            value += c - '0';
	        }
	    }
	    return value;
	}
}