#include <fstream>
#include <vector>
#include <deque>
using namespace std;
deque <int> coada;
vector<int> v[100001];
bool viz[100001];
void bfs(int start)
{
    coada.push_back(start);
    viz[start] = 1;
    while(!coada.empty())
    {
        int nod = coada.front();
        for(int i = 0; i<v[nod].size(); ++i)
            if(!viz[v[nod][i]])
        {
            coada.push_back(v[nod][i]);
            viz[v[nod][i]] = 1;
        }
        coada.pop_front();
    }
}
int main()
{
    int n, m;
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(int i = 1; i<=m; i++)
    {
        int x, y;
        scanf("%d%d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int nr = 0;
    for(int i = 1; i<=n; i++)
        if(!viz[i])
            nr ++,bfs(i);
        printf("%d", nr);
        return 0;
}