#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <complex>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <sstream>

#define REP(i,n) for(long (i)=0;(i)<(n);(i)++)
#define FOR(i,a,b) for(long (i)=(a);(i)<(b);(i)++)
#define RREP(i,a) for(long (i)=(a)-1;(i)>=0;(i)--)
#define FORR(i,a,b) for(long (i)=(a)-1;(i)>=(b);(i)--)
#define MOD 1000000007
#define PI acos(-1.0)
#define DEBUG(C) cout<<C<<endl;
#define PII pair<int,int>
#define PLL pair<long,long>
#define ALL(a) (a).begin(),(a).end()
#define SORT(a) sort((a).begin(),(a).end())
#define RSORT(a) sort((a).begin(),(a).end(),greater<int>())
#define MP(a,b) make_pair(a,b)

typedef long long LL;
typedef unsigned long long ULL;

using namespace std;

string s="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

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

int main(void){
    int N; cin>>N;
    vector<string> V(N);
    map<char,int> mp;
    int cnt=1;
    REP(i,s.size()) mp[s[i]]=cnt++;
    REP(i,N) cin>>V[i];
    ULL umin=ULLONG_MAX;
    REP(i,N){
        char cmax=V[i][0];
        FOR(j,1,V[i].size()){
            cmax=max(cmax,V[i][j]);
        }
        int num=mp[cmax];
        ULL buf=func(V[i].back());
        int cnt=1;
        RREP(j,V[i].size()-1){
            buf+=pow(num,cnt)*func(V[i][j]);
            cnt++;
        }
        umin=min(umin,buf);
    }
    cout<<umin<<endl;
}