#include<fstream>
#include<algorithm>
#include<vector>
#define N 100002
#define pb push_back
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> a[N];
int n,m,sol;
int viz[N];
void dfs(int x)
{
    int lg,i;
    viz[x]=1;
    lg=a[x].size();
    for(i=0;i<lg;i++)
        if(viz[a[x][i]]==0)
            dfs(a[x][i]);
}
void rezolva()
{
    int i;
    for(i=1;i<=n;i++)
        if(viz[i]==0)
        {
            sol++;
            dfs(i);
        }
        g<<sol;
}
void citire()
{
    int i,x,y;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        a[x].pb(y);
        a[y].pb(x);
    }
}
int main()
{
    citire();
    rezolva();
    return 0;
}