#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
template <typename T> inline void read(T &F) {
    int R = 1; F = 0; char CH = getchar();
    for(; !isdigit(CH); CH = getchar()) if(CH == '-') R = -1;
    for(; isdigit(CH); CH = getchar()) F = F * 10 + CH - 48;
    F *= R;
}
inline void file(string str) {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
}
const int N = 1e5 + 10;
string s[N]; int n, ch[N][26], siz[N], flag[N], f[N], tot = 1;
void ins(string str) {
    const int len = str.size();
    int p = 1;
    for(int i = 0; i < len; i++) {
        if(!ch[p][str[i] - 'a']) ch[p][str[i] - 'a'] = ++tot;
        p = ch[p][str[i] - 'a'];
    }
    flag[p] = 1;
}
int fd(string str) {
    const int len = str.size();
    int p = 1;
    for(int i = 0; i < len; i++) {
        if(!ch[p][str[i] - 'a']) return 0;
        p = ch[p][str[i] - 'a'];
    }
    return p;
}
int check(string str) {
    const int len = str.size();
    int p = 1;
    for(int i = 0; i < len; i++) {
        p = ch[p][str[i] - 'a'];
        if(!flag[p]) return false;
    }
    return p;
}

int main() {
    //file("");
    int n; read(n);
    for(int i = 1; i <= n; i++) {
        cin >> s[i]; ins(s[i]);
    }
    sort(s + 1, s + n + 1, [&](const string &x, const string &y) {return x.size() < y.size();});
    f[1] = 1; int ans = 0;
    for(int i = 1; i <= n; i++) {
        int x = fd(s[i].substr(1, s[i].size() - 1));
        if(!f[x]) continue;
        x = check(s[i]);
        if(!x) continue;
        f[x] = 1; ans = s[i].size();
    }
    cout << ans << '\n';
    #ifdef _MagicDuck
        fprintf(stderr, "# Time: %.3lf s", (double)clock() / CLOCKS_PER_SEC);
    #endif
    return 0;
}