#include <bits/stdc++.h>

using namespace std;

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

const int N_MAX = 100000 + 5;
const int INF = 0x3f3f3f3f;

vector<int> vec[N_MAX];
bitset<N_MAX> viz;

int dfs(int node){
    viz[node] = true;
    for(auto v : vec[node])
        if(!viz[v])
            dfs(v);
}

int n, m, ans;

int main()
{
    fin >> n >> m;
    while(m--){
        int a, b;
        fin >> a >> b;
        vec[a].push_back(b);
        vec[b].push_back(a);
    }

    for(int i = 1; i <= n; ++i)
        if(!viz[i]){
            ans ++;
            dfs(i);
        }

    fout << ans;

    return 0;
}