#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <vector<int> > v(200005);
int k = 0;
int viz[100005];


void bfs(int a)
{
    int x;
    queue <int> q;
    viz[a] = k;
    q.push(a);
    while(!q.empty())
    {
        x = q.front();
        q.pop();
        for(unsigned int i = 0; i < v[x].size(); i++)
        {
            if(viz[v[x][i]]==0)
            {
                q.push(v[x][i]);
                viz[v[x][i]] = k;
            }
        }
    }
}

int main()
{
    int n, m, x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(viz[i]==0)
        {
            k++;
            bfs(i);
        }
    }
    fout << k;
    return 0;
}