#include<iostream>
using namespace std;
long ans=(1uLL<<63)-1;
main()
{
	string s;cin>>s;
	for(;cin>>s;)
	{
		int k=0;
		for(int i=0;i<s.size();i++)
		{
			k=k<s[i]?s[i]:k;
		}
		if(k<='9')k-=47;
		else k-=54;
		long p=1,now=0;
		for(int i=s.size();i--;)
		{
			int pos=s[i];
			if(pos<='9')pos-=48;
			else pos-=55;
			now+=pos*p;
			p*=k;
		}
		ans=ans>now?now:ans;
	}
	cout<<ans<<endl;
}