#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

int seen[200000];
vector <int> v[200000];

void DFS(int nod)
{
    seen[nod] = -1;
    for(int j = 0; j<v[nod].size(); j++)
        if(seen[v[nod][j]]==0)
            DFS(v[nod][j]);
}

int main()
{
    int n, m, a, b, i, c = 0;
    in>>n>>m;
    for(i = 0; i<m;i++)
    {
        in>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(i = 1; i<=n; i++)
    {
        if(seen[i]==0)
        {
            c++;
            DFS(i);
        }
    }

    out<<c;
    return 0;
}