#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 100005;

vector<vector<int>>graph;
bitset<NMAX>used;

void dfs(int node)
{
    used[node]=1;
    for(int next:graph[node])
        if(!used[next])
            dfs(next);
}
int main()
{
    int n, m, x, y;
    int nr_conex = 0;
    in >> n >> m;
    graph.assign(n + 1, vector<int>());
    for(int i = 1; i <= m; i++)
    {
        in>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        if(!used[i])
        {
            nr_conex++;
            dfs(i);
        }
    out << nr_conex;
    return 0;
}