#include <iostream>
#include <cmath>
#include <climits>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <functional>
#include <algorithm>
#include <sstream>
#include <map>
#include <set>
#include <utility>

#define endl '\n'
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define DEBUG(x) cout<<#x<<": "<<x<<endl

using namespace std;

typedef pair<int,int> P;
typedef long long int LL;
typedef unsigned long long ULL;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin>>n;
	vector<string> v(n);
	REP(i,n)	cin>>v[i];
	ULL ans=ULLONG_MAX;
	REP(i,n){
		ULL t=0;
		int ki=-1;
		REP(j,SZ(v[i])){
			if(0<=v[i][j]-'0'&&v[i][j]-'0'<10){
				ki=max(ki,v[i][j]-'0');
			}else{
				ki=max(ki,10+v[i][j]-'A');
				//DEBUG(10+v[i][j]-'A');
			}
		}
		ki++;
		DEBUG(ki);
		RREP(j,SZ(v[i])){
			int m;
			if(0<=v[i][j]-'0'&&v[i][j]-'0'<10){
				m=v[i][j]-'0';
			}else{
				m=10+v[i][j]-'A';
			}
			t+=m*pow(ki,(SZ(v[i])-1-j));
			DEBUG(t);
		}
		ans=min(ans,t);
	}
	cout<<ans<<endl;
	return 0;
}