#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100001;

vector<int> a[N];
bool viz[N];
int n, m, nrc;

void dfs(int x)
{
    viz[x] = true;

    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])
        {
            nrc++;
            dfs(i);
        }
    }
    out<<nrc;
    return 0;
}