#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double db;
//#define int long long
const int N=2e5+5;
#define endl '\n'
const double eps=1e-10;

void solve(){
    int n;
    cin>>n;
    vector<string>s(n+5);
    map<string,int>mp;
    for(int i=1;i<=n;i++){
        cin>>s[i];
        mp[s[i]]++;
    }
    int ans=0;
    for(int i=1;i<=n;i++){
        if(s[i].length()>=1e3)continue;
        int f=1;
        for(int j=0;j<s[i].length();j++){
            for(int k=j;k<s[i].length();k++){
                if(mp[s[i].substr(j,k-j+1)]==0){
                    f=0;
                    break;
                }
            }
            if(f==0){
                break;
            }
        }
        if(f){
            int l=s[i].length();
            ans=max(l,ans);
        }
    }
    cout<<ans<<endl;
}
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);
    int T=1;
    //cin>>T;
    while(T--) solve();
    return 0;
}