#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

vector<int>L[100005];

int n,m,x,y,viz[100005],c;

void dfs(int k)
{
    viz[k]=1;
    for(auto i:L[k])
        if(viz[i]==0)
        dfs(i);
}

int main()
{
    cin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        cin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            c++;
            dfs(i);
        }
    }
    cout<<c;
}