#include<algorithm>
#include<complex>
#include<ctype.h>
#include<iomanip>
#include<iostream>
#include<fstream>
#include<map>
#include<math.h>
#include<numeric>
#include<queue>
#include<set>
#include<stack>
#include<stdio.h>
#include<string>
#include<string>
#include<vector>

using namespace std;
typedef unsigned long long ll;

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e19;

ll to_value(char c){
    if('0'<=c && c<='9'){
        return c - '0';
    }
    else{
        return c - 'A' + 10;
    }
}

ll ll_pow(ll a, ll n){
    ll ans = 1;
    FOR(i, 0, n){
        ans *= a;
    }
    return ans;
}

ll decode(string s){
    ll max_value = 0;
    for(char c : s){
        ll v = to_value(c);
        max_value = max(max_value, v);
    }

    ll radix = max_value + 1;
    
    ll sum = 0LL;
    ll L = s.size();
    FOR(i, 0, L){
        char c = s[i];
        ll v = to_value(c);
        v *= ll_pow(radix, L-i-1);
        sum += v;
    }
    
    return sum;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll N;
    cin >> N;

    ll min_value = inf;
    FOR(i, 0, N){
        string s;
        cin >> s;
        
        ll value = decode(s);
        min_value = min(min_value, value);
    }

    cout << setprecision(20);
    p(min_value);
    
    return 0;
}