#include <fstream>
#include <vector>
#define dim 100001

using namespace std;

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

vector <int > v[dim];
bool viz[dim];
int n, m, nr;

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

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