#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define REP1(i, n) for(ll i = 0; i < (n); i++)
#define REP2(i, a, b) for(ll i = (a); i < (b); i++)
#define REP0(n) for(ll iii = 0; iii < (n); iii++)
#define overload3(a, b, c, name, ...) name
#define rep(...) overload3(__VA_ARGS__, REP2, REP1, REP0)(__VA_ARGS__)
#define si(c) (ll)(c.size())

#define vl vector<ll>
#define all(v) v.begin(), v.end()
#define fore(e, v) for(auto &&e : v)

template <typename T, typename S> bool chmax(T &x, const S &y) { return (x < y ? x = y, true : false); }
template <typename T, typename S> bool chmin(T &x, const S &y) { return (x > y ? x = y, true : false); }

int main() {
    ll n;
    cin >> n;
    vector<string> s(n);
    fore(e, s) cin >> e;

    map<string, int> dp;

    int ma = 0;

    sort(all(s), [](const string &x, const string &y) { return si(x) < si(y); });

    fore(e, s) {
        if(si(e) == 1) {
            dp[e] = true;
            ma = 1;
        } else {
            if(dp.count(e.substr(1)) and dp.count(e.substr(0, si(e) - 1))) {
                dp[e] = true;
                ma = si(e);
            }
        }
    }
    cout << ma << endl;
}