// 想定解: やるだけ
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<typename _T> void rc(_T v,_T mn,_T mx){if(v<mn||mx<v){cerr<<"error"<<endl;throw;}}
#define REP(i, n)           for(int(i)=0;(i)<(n);++(i))

int c2n(char c){return(c>='0'&&c<='9'?c-'0':c>='A'&&c<='Z'?c-'A'+10:c>='a'&&c<='z'?c-'a'+10:throw);}

ll solve(const string &s){
    vector<int> v;
    int b = 0;
    for(auto c : s){
        int n = c2n(c);
        v.push_back(n); b = max(b,n+1);
    }
    ll res = 0;
    for(auto n : v) res = (res * b + n);
    return res;
}

int main(){
    int N; cin >> N; rc(N, 1, 1000);
    ll minv = LLONG_MAX;
    REP(i,N){
        string s; cin >> s; rc(int(s.size()), 1, 12);
        minv = min(minv, solve(s));
    }
    cout << minv << endl;
    string s; if(cin >> s) throw;
}