#include <iostream>
#include <vector>
#include <queue>

using namespace std;

vector < vector<int> > graph;
vector <bool> visited;
int n,m;

void bfs(int vertex)
{
    if(vertex < 0 || vertex>n-1) return;
    int element;
    queue<int> q;
    q.push(vertex);
    visited[vertex]=true;

    while(!q.empty()) {
        element=q.front();
        for(int i=0; i<graph[element].size();i++) {
            if(!visited[graph[element][i]])
                q.push(graph[element][i]);
            visited(graph[element][i])=true;
        }
        q.pop();
    }
}

int main()
{
     int x,y,nr=0;
    cin>>n>>m;
    graph.resize(n);
    visited.resize(n,false);
    for(int i=0; i<m; i++) {
        cin>>x>>y;
        x--;
        y--;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(int i=0; i<visited.size() && i<n;i++)
        if(!visited[i]) bfs(i);
}