#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<int>v[200005];
bool f[200005];
int cnt=0;
void dfs(int nod)
{
    if(f[nod]==1)
        return;
    f[nod]=1;
    for (auto it: v[nod])
        dfs(it);
}
int main()
{
    int n,m,i,x,y;
    cin>>n>>m;
    for(i=1; i<=m; i++)
    {
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1; i<=n; i++)
    {
        if(f[i]==0)
        {
            cnt++;
            dfs(i);
        }
    }
    cout<<cnt;
    return 0;
}