#include<fstream>
#include<vector>
using namespace std;

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

int n, m, x, y, cn;
bool viz[100005];
vector <int> v[100005];

void dfs(int nod)
{
    viz[nod] = 1;
    for(auto it: v[nod])
        if(!viz[it])
            dfs(it);
}


int main(unsigned)
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i = 1; i <= n; i++)
        if(!viz[i])
            dfs(i) , cn++;

    fout << cn;
}