#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int NMAX=100000;
vector<int>G[NMAX+5];
int d[NMAX+5], viz[NMAX+5];
int n,cc;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
void bfs(int u)
{
    int v;
    queue<int> q;
    q.push(u);
    viz[u]=cc;
    while(!q.empty())
    {
        u=q.front();
        q.pop();
        for(int j=0;j<(int)G[u].size();j++)
        {
            v=G[u][j];
            if(viz[v]==0)
            {
                viz[v]=cc;
                d[v]=d[u]+1;
                q.push(v);
            }
        }
    }
}
int main()
{
    int m,i,u,v,source;
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>u>>v;
        G[u].push_back(v);
        G[v].push_back(v);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0)
    {
        cc++;
        bfs(i);
    }
    cout<<cc;
    return 0;
}