#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <vector <int>> v;
int f[100001];
void bfs(int i)
{
    f[i]=1;
    for (int j=0;j<v[i].size();j++)
    {
        if (!f[v[i][j]])
        {
            bfs(v[i][j]);
        }
    }
}
int main()
{
    v.resize(100001);
    int n,m;
    fin >>n>>m;
    for (int i=1;i<=m;i++)
    {
        int x,y;
        fin >>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int cnt=0;
    for (int i=1;i<=n;i++)
    {
        if (!f[i])
        {
            bfs(i);
            cnt++;
        }
    }
    fout << cnt;

}