#include <iostream>
#include <vector>
#include <algorithm>

using std::vector;

void DFS(int v, vector<vector<int>>& neighbours, vector<bool>& used, int num_of_component) {
  used[v] = true;
  for (int to : neighbours[v]) {
    if (used[to]) {
      continue;
    }
    DFS(to, neighbours, used, num_of_component);
  }
}

int NumOfComponents(vector<vector<int>>& neighbours, int n) {
  vector<bool> used(n, false);
  int num_of_component = 1;
  for (int i = 0; i < n; ++i) {
    if (!used[i]) {
      std::vector<std::vector<int>> currentNeighbours;
      DFS(i, currentNeighbours, used, num_of_component++);
    }
  }
  return num_of_component;
}

vector<vector<int>> SelectAppropriateGraph(vector<vector<std::pair<int, int>>>& neighboursWithWeight, int x, int n) {
  vector<vector<int>> appropriateGraph(n);
  for (int i = 0; i < neighboursWithWeight.size(); ++i) {
    for (int j = 0; j < neighboursWithWeight[i].size(); ++j) {
      if (neighboursWithWeight[i][j].second > x) {
        appropriateGraph[i].push_back(j);
      }
    }
  }
  return std::move(appropriateGraph);
}

int BinaryFindAnswer(vector<vector<std::pair<int, int>>>& neighboursWithWeight, int max, int initialNum, int n) {
  int left = 0;
  int right = initialNum;
  while (left <= right) {
    int middle = (left + right) / 2;
    vector<vector<int>> neighbours = SelectAppropriateGraph(neighboursWithWeight, middle, n);
    if (NumOfComponents(neighbours, n) == initialNum) { // то есть можно попробовать больше снести
      left = middle;
    } else { // то есть надо меньше снести
      right = middle;
    }
  }
}

int BinarySearch(vector<bool>& a) {
  int left = 0;
  int right = a.size() - 1;
  while (left <= right) {
    int middle = (left + right) / 2;
    if (a[middle]) {
      left = middle + 1;
    } else {
      right = middle - 1;
    }
  }
  if (a[left]) return left;
  return left - 1;
}

int main() {
//  int n, m;
//  std::cin >> n >> m;
//  vector<vector<std::pair<int, int>>> neighboursWithWeight(n);
//  vector<vector<int>> neighbours(n);
//  int maxWeight = 0;
//  for (int j = 0; j < m; ++j) {
//    int l, r, w;
//    std::cin >> l >> r >> w;
//    maxWeight = std::max(maxWeight, w);
//    if (l == r) continue; // ok?
//    neighboursWithWeight[l - 1].emplace_back(r - 1, w);
//    neighboursWithWeight[r - 1].emplace_back(l - 1, w);
//    neighbours[l - 1].push_back(r - 1);
//    neighbours[r - 1].push_back(l - 1);
//  }
//  int initialNumOfComponents = NumOfComponents(neighbours, n);
  vector<bool> a = {1, 1, 0, 0};
  std::cout << BinarySearch(a) + 1;
}