#include <fstream>
#include <vector>

using namespace std;

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

static const int NMAX = 1e5+5;

int n, m;
vector<int> v[NMAX];
bool visited[NMAX];

int ct;

void ReadInput()
{
    fin >> n >> m;
    int x, y;
    for(int i =1; i <= m; ++i)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void Solve(int k)
{
    visited[k] = true;
    for(int i = 0; i< v[k].size(); ++i)
    {
        if(!visited[v[k][i]]){
            Solve(v[k][i]);
        }
        
    }
    
}

int main()
{
    ReadInput();
    for(int i = 1; i<= n; ++i)
    {
        if(!visited[i]){
            Solve(i);
            ct++;
        }
    }
    fout << ct;
    return 0;
}