#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <math.h>
#include <vector>
#include <queue>
#include <algorithm>
#include <sstream>
#include <string>
#include <map>

using namespace std;

#define FOR(I,N) for(int I = 0; I < (int)(N); I++)
#define FIN(V) cout<<V<<endl
#define pb push_back
#define INF (1 << 30)
#define ll long long

typedef pair<int, int> P;

string sValueOf(int v){stringstream ss;ss<<v;return ss.str();}
int parseInt(string v){int i;stringstream ss(v);ss>>i;return i;}
void fast_io() {cin.tie(0); ios::sync_with_stdio(false);}

ll nConvert(string v,int n){
	int i,j;
	ll value = 0;
	FOR(i,v.length()){
		int kazu;
		char c = v[v.length()-i-1];
		if(c>='A'){///文字
			kazu = c-'A'+1;
			kazu+=9;
		}else kazu = c-'0';
		if(kazu>=n)return 1000000000000000000;
		value+=kazu*pow(n,i);
	}
	return value;
}

int main(){
	int i,j;
	int n;
	cin>>n;
	string in;
	ll ans = 1000000000000000000;
	FOR(i,n){
		cin>>in;
		for(j = 2;j<=36;j++){
			ans = min(ans,nConvert(in,j));
		}
	}
	cout<<ans<<endl;
	return 0;
}