#include <bits/stdc++.h>
using namespace std;
#define task "main"
#define F first
#define S second
#define ii pair<int, int>
#define il pair<int, long long>
#define li pair<long long, int>
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b) {a = b; return true;}
return false;
}
template <class T>
void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
for(auto item: container) out << item << separator;
out << finish;
}
const int MAX_N = (int)5e5 + 5;
const int MAX_LEN = (int)3e6 + 6;
int nWord;
string word[MAX_N];
struct NODE {
int child[27];
int par, res = 0;
int firstMax = -1, secondMax = -1;
};
vector<NODE> trie;
NODE newNode;
int nNode = 0;
void updateMax(int &firstMax, int &secondMax, int x) {
if (x > firstMax) secondMax = firstMax, firstMax = x;
else if (x > secondMax) secondMax = x;
}
void addWord(string &s) {
// add new word
int id = 0;
for (char ch : s) {
int c = ch - 'a';
if (!trie[id].child[c]) {
trie[id].child[c] = ++nNode;
trie.push_back(newNode);
trie[nNode].par = id;
}
id = trie[id].child[c];
}
// compute longest subsequence
int parID = trie[id].par;
int a = trie[parID].firstMax, b = trie[parID].secondMax, c = trie[id].res;
int &ans = trie[id].res;
maximize(ans, c + 1); // Case 1: its self, diff at 0 letter
maximize(ans, (c == a ? b : a) + 1); // Case 2: words that have same parent with it, diff at 1 letter
maximize(ans, trie[parID].res + 1); // Case 3: words that ending at its parent node, diff at 1 letter
FOR(c, 0, 25) if (trie[id].child[c])
maximize(ans, trie[trie[id].child[c]].res + 1); // Case 4: words that ending at its children nodes, diff at 1 letter
// update for its parent
updateMax(trie[parID].firstMax, trie[parID].secondMax, ans);
}
void solve() {
cin >> nWord;
FOR(i, 1, nWord) {
cin >> word[i];
reverse(word[i].begin(), word[i].end());
}
trie.push_back(newNode);
FOR(i, 1, nWord) addWord(word[i]);
int ans = 0;
FOR(i, 1, nWord) maximize(ans, trie[i].res);
cout << ans;
}
int32_t main() {
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
bool multitest = 0;
int numTest = 1;
if (multitest) cin >> numTest;
while (numTest--) {
solve();
}
return 0;
}
/* Lak lu theo dieu nhac!!!! */
