#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000007
#define INF 1000000000 //(int)1e9
#define LLINF 8000000000000000000 //(ll)2e18
#define PI  3.1415926536

#define SIZE 100000

int get_number(char a){
    if('0'<=a && a<='9'){
        return a-'0';
    }else{
        return a-'A'+10;
    }
}

int main(){
    int n;
    string s;
    ll ans = LLINF;
    
    scanf("%d",&n);
    
    for(int i=0;i<n;i++){
        int k = 0;
        
        cin >> s;
        
        for(int j=0;j<s.size();j++){
            k = max(k,get_number(s[j]));
        }
        
        k++;
        
        if(k==1){
            ans = 0;
            continue;
        }
        
        ll calc=0;
        ll t = 1;
        
        for(int j=(int)s.size()-1;j>=0;j--){
            calc += t*get_number(s[j]);
            t*=k;
        }
        
        ans = min(ans,calc);
    }
    
    printf("%lld\n",ans);
    
    
    return 0;
}