#include <bits/stdc++.h>

using namespace std;

const int N = 1e5+10; // just a constant for the maximum number of nodes
vector <int> adj[N]; // adjacency list
bool ok = 1; // this indicates if exists a 0-1 coloring for this graph
int c[N]; // c[i] -> color of vertex i

void dfs(int v, int c){
  for(auto &u : adj[v]){
    if (c[u]==-1) dfs(u, !c);
    else if (c[u]==c[v]){
      ok = 0;
      return;
    }
  }
}

int main(){
  // read the graph
  memset(c, -1, sizeof c);
  dfs(1, 0);
}