#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100005];
int n, m, cnt;
bool viz[100005];
void Citire()
{
    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);
    }
}
void dfs(int start)
{
    viz[start] = 1;
    for(auto it: v[start])
        if(viz[it] != 1)
            dfs(it);
}

int main()
{
    Citire();
    for(int i = 1; i <= n; i ++)
    {
        if(viz[i] == 0)
        {
            dfs(i);
            cnt ++;
        }
    }
    fout << cnt;
    return 0;
}