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

using namespace std;

const int N = 100005;

int n, m,nc=0;
vector<int> a[N+1];
bitset <N+1> viz;

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

void dfs(int x)
{
    viz[x]=1;
    for (auto y: a[x])
    {
        if (!viz[y])
        {
            dfs(y);
        }
    }
}

int main()
{
    in>>n>>m;
    for (int i=0; i<m; i++)
    {
        int x,y;
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (int i=1; i<=n; i++)
    {
        if (viz[i]==0)
        {
            nc++;
            dfs(i);
        }
    }
    out<<nc;

    return 0;
}