#include <bits/stdc++.h>
using namespace std;

#define int long long
template<typename T>
void chmin(T &a,T b){
  if(a>b)a=b;
}
template<typename T>
void chmax(T &a,T b){
  if(a<b)a=b;
}

signed main(){
  int n;cin>>n;
  int ans=5e18;
  while(n--){
    string s;cin>>s;
    int T=0;
    for(auto p:s){
      if(p>='0'&&p<='9')chmax(T,(int)(p-'0'));
      else chmax(T,(int)(p-'A'+10));
    }
    int res=0;
    for(auto p:s){
      res*=T+1;
      if(p>='0'&&p<='9')res+=(int)(p-'0');
      else res+=(int)(p-'A'+10);
    }
    chmin(ans,res);
  }
  cout<<ans<<endl;
}