#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 5000000000000000000



int main(){	
	
	int N;
	cin>>N;
	
	long long ans = Inf;
	
	rep(_,N){
		string s;
		cin>>s;
		vector<int> t(s.size(),0);
		rep(i,s.size()){
			if(isdigit(s[i]))t[i] = s[i]-'0';
			else t[i] = 10 + (s[i]-'A');
		}
		
		int b = 2;
		rep(i,t.size())b = max(b,t[i]+1);
		long long cur = 0LL;
		rep(i,t.size()){
			cur *= b;
			cur += t[i];
		}
		ans = min(ans,cur);
	}
	
	cout<<ans<<endl;
	
	return 0;
	
}