#include <bits/stdc++.h>
#define REP(i,n,N) for(int i=(n);i<(int) N;i++)
#define p(s) cout<<(s)<<endl
typedef long long ll;
using namespace std;
const ll inf=LONG_LONG_MAX;

int main(){
	int n;
	cin>>n;
	string s;

	ll ans=inf;
	REP(i,0,n){
		cin>>s;
		ll mx=0;
		REP(j,0,s.size()){
			if(isdigit(s[j]))	mx=max<ll>(mx,s[j]-'0');
			else mx=max<ll>(mx,s[j]-'A'+10);
		}
		mx++;
		ll tmp=0;
		REP(j,0,s.size()){
			tmp*=mx;
			if(isdigit(s[j])) tmp+=s[j]-'0';
			else tmp+=s[j]-'A'+10;
		}
		ans=min<ll>(ans,tmp);
	}
	p(ans);
	return 0;
}