#include <cstdio>
#include <vector>
#include <deque>
using namespace std;
///componente conexe
vector<int> v[100005];
deque<int> q;
bool viz[100005];
void BFS(int start)
{
    viz[start] = 1;
    q.push_back(start);
    while(!q.empty())
    {
        int nod = q.front();
        for(int i = 0; i< v[nod].size(); i++)
            if(!viz[v[nod][i]])
            {
                q.push_back(v[nod][i]);
                viz[v[nod][i]] = 1;
            }
            q.pop_front();
    }
}
int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int n, m;
    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;
}