#include <fstream>
#include <vector>

using namespace std;

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

const int nmax=100000;
vector <int> g[nmax+1];
bool u[nmax+1];

void dfs (int x) {
    u[x]=1;
    for (int i=0; i<int(g[x].size()); i++) {
        int xn=g[x][i];
        if (u[xn]==0) {
            dfs(xn);
        }
    }
}

int main () {
    int n, m;
    fin>>n>>m;

    for (int i=1; i<=m; i++) {
        int x, y;
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }

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

    fout<<sol<<"\n";

    return 0;
}