#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int N=100010;

vector <int> v[N];

int n,m,x,y,i,c,viz[N];

void dfs(int i);

int main()
{
    fin>>n>>m;
    for(;m;m--)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(!viz[i])
    {
        c++;
        dfs(i);
    }
    fout<<c<<'\n';
    return 0;
}

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