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9
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 1

#include <bits/stdc++.h>
using namespace std;
int n, tot, Max, ctr, ans = 1, Head[100000 + 5], Dep[100000 + 5],
                      Fa[100000 + 5], T[100000 + 5], Hash_1[100000 + 5],
                      Hash_2[100000 + 5], Max_Dep[100000 + 5];
bool Flag[100000 + 5];
map<pair<int, int>, bool> Map;
struct Edge {
  int next, node;
} h[100000 + 5 << 1];
inline void addedge(int u, int v) {
  h[++tot].next = Head[u], Head[u] = tot;
  h[tot].node = v;
}
inline void deledge(int u, int v) {
  if (h[Head[u]].node == v)
    Head[u] = h[Head[u]].next;
  else
    for (int i = Head[u]; h[i].next; i = h[i].next)
      if (h[h[i].next].node == v) {
        h[i].next = h[h[i].next].next;
        break;
      }
}
inline void dfs(int z, int fa) {
  if (!fa)
    Dep[z] = 0, Max = z;
  else
    Max = Dep[z] > Dep[Max] ? z : Max;
  for (int i = Head[z]; i; i = h[i].next) {
    int d = h[i].node;
    if (d == fa) continue;
    Fa[d] = z, Dep[d] = Dep[z] + 1;
    dfs(d, z);
  }
}
inline void Go(int &u, int step) {
  while (step--) u = Fa[u];
}
inline bool cmp(int u, int v) {
  return make_pair(Hash_1[u], Hash_2[u]) < make_pair(Hash_1[v], Hash_2[v]);
}
inline void DFS(int z, int fa) {
  if (!fa) Dep[z] = 0;
  Hash_1[z] = Hash_2[z] = 233, Max_Dep[z] = z;
  for (int i = Head[z]; i; i = h[i].next) {
    int d = h[i].node;
    if (d == fa) continue;
    Dep[d] = Dep[z] + 1, Fa[d] = z;
    DFS(d, z);
    Max_Dep[z] = Dep[Max_Dep[d]] > Dep[Max_Dep[z]] ? Max_Dep[d] : Max_Dep[z];
  }
  T[0] = 0;
  for (int i = Head[z]; i; i = h[i].next) {
    int d = h[i].node;
    if (d == fa) continue;
    T[++T[0]] = i;
  }
  sort(T + 1, T + T[0] + 1, cmp);
  for (int i = 1; i <= T[0]; i++) {
    Hash_1[z] = (1LL * Hash_1[z] * 1306213 + Hash_1[T[i]] + 233) % 998244353;
    Hash_2[z] = (1LL * Hash_2[z] * 1301551 + Hash_2[T[i]] + 233) % 1000000007;
  }
  if (Map.find(make_pair(Hash_1[z], Hash_2[z])) != Map.end()) Flag[z] = 1;
  Map[make_pair(Hash_1[z], Hash_2[z])] = 1;
}
int main() {
  scanf("%d", &n);
  for (int i = 1, u, v; i < n; i++) {
    scanf("%d%d", &u, &v);
    addedge(u, v), addedge(v, u);
  }
  dfs(1, 0), dfs(Max, 0);
  Go(ctr = Max, Dep[Max] >> 1);
  if (Dep[Max] & 1) {
    int tmp = n + 1;
    deledge(ctr, Fa[ctr]);
    deledge(Fa[ctr], ctr);
    addedge(tmp, ctr), addedge(tmp, Fa[ctr]);
    ctr = tmp;
  }
  DFS(ctr, 0);
  for (int i = 1; i <= n; i++)
    if (Flag[i] && Dep[Max_Dep[i]] - Dep[i] > Dep[Max_Dep[ans]] - Dep[ans])
      ans = i;
  printf("%d\n", Max_Dep[ans]);
  return 0;
}
