#include <iostream>
#include<vector>
#include<fstream>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
/// parcurgere dfs graf neorientat

const int NMAX=1e5;
vector<int> L[NMAX+1];
int vis[NMAX+1];
void dfs(int node) ///O(n+m)
{
    vis[node]=1;
    for(auto vec: L[node])
    {
        if(vis[vec]==0)
            dfs(vec);
    }
}
int main()
{
    int n,m;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int cc=0;
    for(int i=1;i<=n;i++)
        if(vis[i]==0)
    {
        cc++;
        dfs(i);
    }
    fout<<cc;
    fin.close();
    fout.close();
    return 0;
}