#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    
    
    long long ans = LLONG_MAX;
    int N;
    cin >> N;
    for ( int i = 0; i < N; i++ ) {
        string S;
        cin >> S;
        int m = 0;
        for ( int j = 0; j < S.length(); j++ ) {
            if ( isdigit(S[j]) ) { m = max( m, S[j] - '0' ); }
            else { m = max( m, S[j]-'A'+10 ); }
        }
        m++;
        long long a = 0;
        for ( int j = S.length()-1; j >= 0 ; j-- ) {
            long long x = 1;
            for ( int k = 0; k < S.length()-1-j; k++ ) {
                x *= m;
            }
            if ( isdigit(S[j]) ) {                
                x *= S[j] - '0';
            }
            else {
                x *= S[j] - 'A' + 10;
            }
            a += x;
        }
        
        ans = min( ans, a );
    }
    
    
    
    cout << ans << endl;
    
    return 0;
}