# include <bits/stdc++.h>

using namespace std;

int n,m,i,x,y,compcon;
bool viz[100010];
vector <int> a[100010];

void dfs(int x)
{
    viz[x]=1;
    for(i=1;i<=a[x][0];++i)
        if(viz[i]==0)
            dfs(i);

}
int main()
{

    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
    while(i<m)
    {
        f>>x>>y;
        a[x].push_back (y);
        a[y].push_back (x);
        ++i;
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            compcon++;
            dfs(i);
        }

    }
    g<<compcon<<'\n';
    return 0;
}