#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 ) {
            ++ sol;
            dfs(i);
        }
    }

    fout << sol << "\n";

    return 0;
}