#include <fstream>
#include <vector>

using namespace std;

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

vector<int> a[100001];
bool f[100001];
int rez;

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

int main()
{
    int n,m;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(f[i]==0)
            {
                dfs(i);
                rez++;
            }
    fout<<rez;
    return 0;
}