#include <iostream>
#include <fstream>
#include <vector>
#define nmax 1000005

using namespace std;

int n,m,x,y,cmp;
vector <int>a[nmax];
bool viz[nmax];

int dfs(int x)
{
    for(int i=0; i<a[x].size(); i++)
        if(viz[a[x][i]]==0)
        {
            viz[a[x][i]]=1;
            dfs(a[x][i]);
        }

}
int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1;i<=n; i++)
    {
        if(viz[i]==0)
        {
            cmp++;
            dfs(i);
        }
    }
    g<<cmp;
    return 0;
}