#include <fstream>
#include <vector>
#include <queue>
#define len 100010
#define pb push_back

using namespace std;

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

vector<unsigned> v[len];

queue<unsigned> q;

unsigned N, M, count;
bool viz[len];

void bfs(unsigned nod)
{
    q.push(nod);
    viz[nod] = true;
    while(!q.empty())
    {
        for(unsigned k = 0; k < v[q.front()].size(); ++k)
            if(!viz[v[q.front()][k]])
            {
                viz[v[q.front()][k]] = true;
                q.push(v[q.front()][k]);
            }
        q.pop();
    }
}

int main()
{
    in >> N >> M;
    for(unsigned i = 1; i <= M; ++i)
    {
        unsigned x, y;
        in >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }
    for(unsigned i = 1; i <= N; ++i)
        if(!viz[i])
        {
            ++count;
            bfs(i);
        }
    out << count;
    return 0;
}