We call a sequence of strings t1, ..., tk a journey of length k, if for each i > 1 ti is a substring of ti - 1 and length of ti is strictly less than length of ti - 1. For example, {ab, b} is a journey, but {ab, c} and {a, a} are not.

Define a journey on string s as journey t1, ..., tk, such that all its parts can be nested inside s in such a way that there exists a sequence of strings u1, ..., uk + 1 (each of these strings can be empty) and s = u1 t1 u2 t2... uk tk uk + 1. As an example, {ab, b} is a journey on string abb, but not on bab because the journey strings ti should appear from the left to the right.

The length of a journey on a string is the number of strings in it. Determine the maximum possible length of a journey on the given string s.

Input

The first line contains a single integer n (1 ≤ n ≤ 500 000) — the length of string s.

The second line contains the string s itself, consisting of n lowercase Latin letters.

Output

Print one number — the maximum possible length of string journey on s.

Examples

Input

7
abcdbcc


Output

3


Input

4
bbcb


Output

2

Note

In the first sample, the string journey of maximum length is {abcd, bc, c}.

In the second sample, one of the suitable journeys is {bb, b}.
#include <bits/stdc++.h>
using std::max;
using std::min;
const int inf = 0x3f3f3f3f, Inf = 0x7fffffff;
const long long INF = 0x3f3f3f3f3f3f3f3f;
__inline__ __attribute__((always_inline)) unsigned int rnd() {
  static unsigned int seed = 416;
  return seed += 0x71dad4bfu, seed ^= seed >> 5, seed += 0xc6f74d88u,
         seed ^= seed << 17, seed += 0x25e6561u, seed ^= seed >> 13;
}
template <typename _Tp>
_Tp gcd(const _Tp &a, const _Tp &b) {
  return (!b) ? a : gcd(b, a % b);
}
template <typename _Tp>
__inline__ __attribute__((always_inline)) _Tp abs(const _Tp &a) {
  return a >= 0 ? a : -a;
}
template <typename _Tp>
__inline__ __attribute__((always_inline)) void chmax(_Tp &a, const _Tp &b) {
  (a < b) && (a = b);
}
template <typename _Tp>
__inline__ __attribute__((always_inline)) void chmin(_Tp &a, const _Tp &b) {
  (b < a) && (a = b);
}
template <typename _Tp>
__inline__ __attribute__((always_inline)) void read(_Tp &x) {
  char ch(getchar());
  bool f(false);
  while (!isdigit(ch)) f |= ch == 45, ch = getchar();
  x = ch & 15, ch = getchar();
  while (isdigit(ch)) x = (((x << 2) + x) << 1) + (ch & 15), ch = getchar();
  f && (x = -x);
}
template <typename _Tp, typename... Args>
__inline__ __attribute__((always_inline)) void read(_Tp &t, Args &...args) {
  read(t);
  read(args...);
}
template <typename _Tp, typename... Args>
__inline__ __attribute__((always_inline)) _Tp min(const _Tp &a, const _Tp &b,
                                                  const Args &...args) {
  return a < b ? min(a, args...) : min(b, args...);
}
template <typename _Tp, typename... Args>
__inline__ __attribute__((always_inline)) _Tp max(const _Tp &a, const _Tp &b,
                                                  const Args &...args) {
  return a < b ? max(b, args...) : max(a, args...);
}
__inline__ __attribute__((always_inline)) int read_str(char *s) {
  char ch(getchar());
  while (ch == ' ' || ch == '\r' || ch == '\n') ch = getchar();
  char *tar = s;
  *tar = ch, ch = getchar();
  while (ch != ' ' && ch != '\r' && ch != '\n' && ch != EOF)
    *(++tar) = ch, ch = getchar();
  return tar - s + 1;
}
const int N = 500005;
const int mod = 998244853;
template <typename _Tp1, typename _Tp2>
__inline__ __attribute__((always_inline)) void add(_Tp1 &a, _Tp2 b) {
  (a += b) >= mod && (a -= mod);
}
template <typename _Tp1, typename _Tp2>
__inline__ __attribute__((always_inline)) void sub(_Tp1 &a, _Tp2 b) {
  (a -= b) < 0 && (a += mod);
}
const int base = 23333;
char s[N];
unsigned long long B[5 + ((mod + 63) >> 6)];
__inline__ __attribute__((always_inline)) void set(int pos) {
  B[pos >> 6] |= 1ull << (pos & 63);
}
__inline__ __attribute__((always_inline)) void reset(int pos) {
  B[pos >> 6] &= ~(1ull << (pos & 63));
}
__inline__ __attribute__((always_inline)) bool test(int pos) {
  return (B[pos >> 6] >> (pos & 63)) & 1;
}
int f[N];
int dp[N];
int main() {
  int n;
  read(n);
  read_str(s + 1);
  for (int i = 1; i <= n; ++i) s[i] -= 96;
  int mid;
  for (int i = 1; i <= n; ++i) f[i] = s[i], dp[i] = 1;
  for (mid = 2; mid <= 1000; ++mid) {
    bool flag = false;
    for (int i = n - mid + 1; i >= 1; --i) {
      if (dp[i + mid] >= mid - 1) set(f[i + mid]);
      if ((dp[i] == mid - 1 && test(f[i])) ||
          (dp[i + 1] >= mid - 1 && test(f[i + 1]))) {
        dp[i] = mid;
        flag = true;
      }
    }
    if (!flag) {
      --mid;
      break;
    }
    for (int i = 1; i <= n; ++i)
      if (dp[i] >= mid - 1) reset(f[i]);
    for (int i = n - mid + 1; i >= 1; --i)
      f[i] = (1ll * f[i] * base + s[i + mid - 1]) % mod;
  }
  printf("%d\n", mid);
  return 0;
}
