#include <fstream>
#include <vector>

using namespace std;
const int M=1e5;
vector<int>graf[M];
bool used[M];
void DFS(int node)
{
    used[node]=true;
    for(int i=0;i<graf[node].size();i++)
    {
        int neighbour=graf[node][i];
        if(!used[neighbour])
            DFS(neighbour);
    }
}

int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n,m;
    in>>n>>m;
    for(int i=0;i<m;i++)
    {
        int x,y;
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    int co=0;
    for(int i=1;i<=n;i++)
    {
        if(!used[i])
        {
            DFS(i);
            co++;
        }
    }
    out<<co;
    in.close();
    out.close();
    return 0;
}