#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    long long answer = 8e18;
    while(N--){
        string s; cin >> s;
        int maxv = 0;
        for(auto c : s){
            if(isupper(c)) maxv = max(maxv,10+c-'A');
            else maxv = max(maxv,c-'0');
        }
        maxv++;
        long long now = 0;
        for(auto c : s){
            now *= maxv;
            if(isupper(c)) now += 10+c-'A';
            else now += c-'0';
        }
        answer = min(answer,now);
    }
    cout << answer << endl;
}