#include <fstream>
#include<vector>
using namespace std;
int vf[100001];
struct graf
{
    vector<int>v;
}graf[100001];
void dfs (int a)
{
    int i;
    vf[a]=1;
    for (i=0;i<graf[a].v.size();i++)
    {
        if (vf[graf[a].v[i]]==0)
        {
            dfs(graf[a].v[i]);
        }
    }
}
int main()
{
    ifstream cin ("dfs.in");
    ofstream cout("dfs.out");
    int n, m, i, x, y, cnt=0;
    cin>>n>>m;
    for (i=1;i<=m;i++)
    {
        cin>>x>>y;
        graf[x].v.push_back(y);
        graf[y].v.push_back(x);
    }
    for (i=1;i<=n;i++)
    {
        if (vf[i]==0)
        {
            cnt++;
            dfs(i);
        }
    }
    cout<<cnt;
    return 0;
}