#include <fstream>
#include <vector>

using namespace std;

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

const int Max = 100010;

vector<int> v[Max];
char vaz[Max];

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

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

    out << nr;
    return 0;
}