#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
#define Nmax 100005

using namespace std;

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

int n, m, x, y, cc;
vector <int> v[Nmax];
bitset <Nmax> seen;

void dfs(int x)
{
    seen[x]=1;
    for (auto y:v[x])
    {
        if(seen[y] == 1) continue;
        dfs(y);
    }
}

int main()
{
    f >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
        if(seen[i] == 0)
        {
            cc++;
            dfs(i);
        }

    g << cc;
    return 0;
}