#include <bits/stdc++.h>

using namespace std;

int n,m,viz[100005];
vector<int>a[200000];
queue<int> q;

inline void Citire()
{
    int i,x,y;
    ifstream fin("dfs.in");
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    fin.close();
}

void DFS(int v)
{
    int i, j;
    viz[v] = 1;
    for (i = 0; i < a[v].size(); i++)
    {
        j = a[v][i];
        if (!viz[j]) DFS(j);
    }
}

inline void Sol()
{
    int i,nr=0;
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            nr++;
            DFS(i);
        }
    ofstream fout("dfs.out");
    fout<<nr<<"\n";
    fout.close();
}

int main()
{
    Citire();
    Sol();
    return 0;
}