#include <bits/stdc++.h>
using namespace std;
#define SPEED \
ios_base::sync_with_stdio(0); \
cin.tie(NULL); \
cout.tie(NULL);
#define ALL(x) x.begin(), x.end()
#define sz(x) ((int)(x.size()))
#define int long long
#define vi vector<int>
#define pii pair<int, int>
const int MAXN = 1000010;
const int HASH1 = 3137;
const int HASH2 = 10007;
const int MOD = 1000000007;
map<pii, pii> dp;
int powh1[MAXN], powh2[MAXN], previous[MAXN];
int res, res_idx;
void solve() {
memset(previous, -1, sizeof(previous));
powh1[0] = powh2[0] = 1;
for (int i = 1; i < MAXN; ++i) {
powh1[i] = (powh1[i - 1] * HASH1) % MOD;
powh2[i] = (powh2[i - 1] * HASH2) % MOD;
}
int n;
cin >> n;
res = 0;
res_idx = -1;
for (int j = 0; j < n; ++j) {
string s;
cin >> s;
int m = sz(s);
int h_front1 = 0, h_back1 = 0;
int h_front2 = 0, h_back2 = 0;
int best = 0;
for (int i = 0; i < m; ++i) {
h_back1 = (h_back1 * HASH1 + s[m - 1 - i]) % MOD;
h_front1 = (h_front1 + powh1[i] * s[i]) % MOD;
h_back2 = (h_back2 * HASH2 + s[m - 1 - i]) % MOD;
h_front2 = (h_front2 + powh2[i] * s[i]) % MOD;
if (h_front1 == h_back1 && h_front2 == h_back2) {
auto it = dp.find({h_front1, h_front2});
if (it != dp.end() && best < it->second.first) {
best = it->second.first;
previous[j] = it->second.second;
}
}
}
dp[{h_front1, h_front2}] = {best + 1, j};
if (best + 1 > res) {
res = best + 1;
res_idx = j;
}
}
cout << res << endl;
}
signed main() {
SPEED;
solve();
return 0;
}
