#include <fstream>
#include <vector>

using namespace std;

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

int n, m, x, y, visit[100001], nr;
vector <int> v[100001];

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

int main()
{
    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(visit[i] == 0){
            dfs(i);
            nr++;
        }
    fout << nr;
    return 0;
}