#include <bits/stdc++.h>
#define NUM 100005
using namespace std;
vector<int> graf[NUM];
vector<int> viz(NUM, 0);
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m, comp, a, b;
void dfs(int nod)
{
    viz[nod] = 1;
    for(int i = 0; i < graf[nod].size(); ++i)
        if(!viz[graf[nod][i]])
            dfs(graf[nod][i]);
}
int main()
{
    f >> n >> m;
    while(m)
    {
        f >> a >> b;
        graf[a].push_back(b);
        graf[b].push_back(a);
        m--;
    }
    for(int i = 1; i <= n; ++i)
        if(!viz[i])
        {
            comp++;
            dfs(i);
        }
    g << comp;
    f.close();
    g.close();
}