#include <bits/stdc++.h>

using namespace std;

vector<int> ZFunction(string s) {
  int n = s.size();
  vector<int> z(n, 0);
  int L = 0, R = 0;
  for (int i = 1; i < n; i++) {
    if (i > R) {
      L = R = i;
      while (R < n && s[R - L] == s[R]) R++;
      z[i] = R - L; R--;
    } else {
      int k = i-L;
      if (z[k] < R - i + 1) z[i] = z[k];
      else {
        L = i;
        while (R < n && s[R - L] == s[R]) R++;
        z[i] = R - L; R--;
      }
    }
  }
  return z;
}

struct DSU {
  int n; vector<int> L, R; vector<bool> ers;
  DSU(int n) : n(n), L(n), R(n), ers(n, false) {
    for (int i = 0; i < n; ++i)
      L[i] = R[i] = i;
  }
  int Erase(int x) {
    int ret = -1;

    int l = (x == 0 ? -1 : L[x - 1]);
    int r = (x + 1 == n ? -1 : R[x + 1]);
    if (l != -1 && r != -1) {
      ret = r - l;
    }
    if (l != -1) R[l + 1] = r;
    if (r != -1) L[r - 1] = l;
    ers[x] = true;
    return ret;
  }
};

int main() {
  string s; cin >> s;
  int n = s.size();
  auto z = ZFunction(s);
  vector<int> dp(n, 0);
  z[0] = n;

  vector<pair<int, int>> v(n);
  for (int i = 0; i < n; ++i)
    v[i] = make_pair(z[i], i);
  sort(v.begin(), v.end());

  int at = 0;
  int max_diff = 1;
  DSU dsu(n);

  for (int len = 1; len <= n; ++len) {
    while (at < n && v[at].first < len) {
      max_diff = max(max_diff, dsu.Erase(v[at].second));
      ++at;
    }
    if (max_diff <= len && !dsu.ers[n - len]) {
      cout << len << endl;
      return 0;
    }
  }

  assert(false);
}