#include<iostream>
#include<fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int> v[200001];
int i,n,x,y,m,ind[200001];

void dfs(int nod)
{
ind[nod]=1;
for(int j=0;j<v[nod].size();j++)
    if(ind[v[nod][j]]==0)
    {dfs(v[nod][j]); ind[v[nod][j]]=1;}
}

int main()
{
    f>>n>>m;
    while(m>0)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
        m--;
    }

    int cc=0;
    for(i=1;i<=n;i++)
        if (ind[i]==0){dfs(i); cc++;}


    g<<cc;
    f.close();
    g.close();
    return 0;
}