#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

const int MaxN = 100005;
vector<int> G[MaxN];
int N, M;
bool v[MaxN];

void Read();
void DFS(int x);

int main()
{
    Read();
    int cnt = 0;

    for(int i = 1; i <= N; ++i)
        if(!v[i])
    {
        DFS(i);
        ++cnt;
    }

    fout << cnt << '\n';

    fout.close();
    return 0;
}

void Read()
{
    fin >> N >> M;

    while(M--)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    fin.close();
}
void DFS(int x)
{
    v[x] = true;
    for(const int y : G[x])
        if(!v[y])
            DFS(y);
}