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

using namespace std;

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

vector < int > L[1001];
int n, m;
bool viz[1001];

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

inline void DFS(int k)
{
    viz[k] = 1;
    for(int i = 0; i < L[k].size(); i++)
        if(!(viz[L[k][i]]))
            DFS(L[k][i]);
}

int main()
{
    int con = 0;
    Read();
    for(int i = 1; i <= n; i++)
        if(!viz[i])
            {
                DFS(i);
                con++;
            }
    fout << con;
    fout.close();
    return 0;
}