#include <bits/stdc++.h>
using namespace std;
ifstream f ("dfs.in"); ofstream g ("dfs.out");
vector <int> L[100001];
bool viz[100001];
int n,m,nr;
void dfs(int s)
{   viz[s]=true;
    for(int i = 0;i < L[s].size();++i)
       if(viz[L[s][i]] == false) dfs(L[s][i]);
}
int main()
{   f>>n>>m;
    for(int x,y,i = 0;i < m;++i)
    {   f >> x >> y;
        L[x].push_back(y);    //Edge from vertex x to vertex y
        L[y].push_back(x);    //Edge from vertex y to vertex x
    }
    for(int i = 1;i <= n;++i)
        if(viz[i] == false) { dfs(i); nr++; }
    g<<nr<<'\n';
    g.close();
    f.close();
    return 0;
}