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#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-8;
const double pi = acos(-1.0);
template <class T>
int chkmin(T &a, T b) {
  return a > b ? a = b, 1 : 0;
}
template <class T>
int chkmax(T &a, T b) {
  return a < b ? a = b, 1 : 0;
}
template <class T>
T sqr(T a) {
  return a * a;
}
template <class T>
T mmin(T a, T b) {
  return a < b ? a : b;
}
template <class T>
T mmax(T a, T b) {
  return a > b ? a : b;
}
template <class T>
T aabs(T a) {
  return a < 0 ? -a : a;
}
template <class T>
int dcmp(T a, T b) {
  return a > b;
}
template <int *a>
int cmp_a(int first, int second) {
  return a[first] < a[second];
}
namespace io {
const int SIZE = (1 << 21) + 1;
char ibuf[SIZE], *iS, *iT, obuf[SIZE], *oS = obuf, *oT = oS + SIZE - 1, c,
                                       qu[55];
int f, qr;
inline void flush() {
  fwrite(obuf, 1, oS - obuf, stdout);
  oS = obuf;
}
inline void putc(char first) {
  *oS++ = first;
  if (oS == oT) flush();
}
inline bool read(signed &first) {
  for (f = 1, c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                              (iS == iT ? EOF : *iS++))
                            : *iS++);
       c < '0' || c > '9';
       c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                       (iS == iT ? EOF : *iS++))
                     : *iS++))
    if (c == '-')
      f = -1;
    else if (c == EOF)
      return 0;
  for (first = 0; c <= '9' && c >= '0';
       c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                       (iS == iT ? EOF : *iS++))
                     : *iS++))
    first = first * 10 + (c & 15);
  first *= f;
  return 1;
}
inline bool read(long long &first) {
  for (f = 1, c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                              (iS == iT ? EOF : *iS++))
                            : *iS++);
       c < '0' || c > '9';
       c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                       (iS == iT ? EOF : *iS++))
                     : *iS++))
    if (c == '-')
      f = -1;
    else if (c == EOF)
      return 0;
  for (first = 0; c <= '9' && c >= '0';
       c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                       (iS == iT ? EOF : *iS++))
                     : *iS++))
    first = first * 10 + (c & 15);
  first *= f;
  return 1;
}
inline bool read(char &first) {
  first = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                       (iS == iT ? EOF : *iS++))
                    : *iS++);
  return first != EOF;
}
inline bool read(char *first) {
  while ((*first = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                                (iS == iT ? EOF : *iS++))
                             : *iS++)) == '\n' ||
         *first == ' ' || *first == '\r')
    if (*first == EOF) return 0;
  while (!(*first == '\n' || *first == ' ' || *first == '\r'))
    *(++first) = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),
                              (iS == iT ? EOF : *iS++))
                           : *iS++);
  *first = 0;
  return 1;
}
template <typename A, typename... B>
inline bool read(A &first, B &...second) {
  return read(first) && read(second...);
}
inline bool write(signed first) {
  if (!first) putc('0');
  if (first < 0) putc('-'), first = -first;
  while (first) qu[++qr] = first % 10 + '0', first /= 10;
  while (qr) putc(qu[qr--]);
  return 0;
}
inline bool write(long long first) {
  if (!first) putc('0');
  if (first < 0) putc('-'), first = -first;
  while (first) qu[++qr] = first % 10 + '0', first /= 10;
  while (qr) putc(qu[qr--]);
  return 0;
}
inline bool write(char first) {
  putc(first);
  return 0;
}
inline bool write(const char *first) {
  while (*first) {
    putc(*first);
    ++first;
  }
  return 0;
}
inline bool write(char *first) {
  while (*first) {
    putc(*first);
    ++first;
  }
  return 0;
}
template <typename A, typename... B>
inline bool write(A first, B... second) {
  return write(first) || write(second...);
}
struct Flusher_ {
  ~Flusher_() { flush(); }
} io_flusher_;
}  // namespace io
using io ::putc;
using io ::read;
using io ::write;
char str[200005], *s[100005];
int len[100005];
int ans;
void check(int w, char chr, int lst) {
  for (int i = 1; i <= lst; ++i) {
    for (int j = 0; j < len[i]; ++j)
      if (s[i][j] == chr) chkmax(ans, w + 1);
  }
}
int main() {
  int n;
  read(n);
  s[1] = str;
  for (int i = 1; i <= n; ++i) {
    read(s[i]);
    s[i + 1] = s[i] + (len[i] = strlen(s[i])) + 1;
  }
  ans = 0;
  char pc = 0;
  int cnt = 0;
  for (int i = 0; i < len[n]; ++i) {
    if (s[n][i] != pc) {
      cnt = 0;
      pc = s[n][i];
    }
    chkmax(ans, ++cnt);
  }
  for (int i = 0; i < len[n]; ++i) {
    if (s[n][i] != s[n][0]) {
      int cnt = i;
      for (int j = len[n] - 1; j >= 0; --j) {
        if (s[n][j] == s[n][0])
          ++cnt;
        else
          break;
      }
      check(cnt, s[n][0], n - 1);
      if (cnt == i - 1) {
        cnt = 0;
        for (int j = len[n] - 1; j >= 0; --j) {
          if (s[n][j] == s[n][len[n] - 1])
            ++cnt;
          else
            break;
        }
        check(cnt, s[n][len[n] - 1], n - 1);
      }
      write(ans, '\n');
      return 0;
    }
  }
  int pre = len[n];
  for (int i = n - 1; i; --i) {
    int l = 1, mx = 1;
    for (int j = 0; j < len[i]; ++j) {
      if (s[i][j] != s[n][0]) l = 0;
      chkmax(mx, ++l);
    }
    chkmax(ans, mx * (pre + 1) - 1);
    if (mx != len[i] + 1) {
      int cnt = 2;
      for (int j = 0; j < len[i]; ++j) {
        if (s[i][j] != s[n][0])
          break;
        else
          ++cnt;
      }
      for (int j = len[i] - 1; j; --j) {
        if (s[i][j] != s[n][0])
          break;
        else
          ++cnt;
      }
      check(cnt * (pre + 1) - 2, s[n][0], i - 1);
      write(ans, '\n');
      return 0;
    }
  }
  return write(ans, '\n');
  return 0;
}
