#include<iostream>
using namespace std;
typedef long long ll;

ll getnum(int digit, string s){
    ll res = 0;
    ll base = 1;
    for(int i = s.size()-1; i >= 0; i--){
        char x = s[i];
        if(x <= '9') res += ll(x-'0')*base;
        else         res += ll(x-'A'+10)*base;
        base *= ll(digit);
    }
    return res;
}
int main(){
    int n;
    cin >> n;
    string s;
    ll ans = 0;
    while(n-- > 0){
        cin >> s;
        char m = '0';
        for(char x : s){
            m = max(m,x);
        }
        ll now;
        if(m <= '9') now = getnum(m-'0'+1,s);
        else         now = getnum(m-'A'+11,s);
        ans = min(ans,now);
    }
    
    cout << ans << endl;
    return 0;
}