#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m, viz[100005], cnt;
vector<int> G[100005];
void DFS(int x)
{
    viz[x] = cnt;
    for(auto e : G[x])
        if(!viz[e]) DFS(e);
}
int main()
{
    ios_base::sync_with_stdio(0);
    fin.tie(0);
    fout.tie(0);
    int i,j;
    fin >> n >> m;
    while(m--)
    {
        fin >> i >> j;
        G[i].push_back(j);
        G[j].push_back(i);
    }

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