#include <iostream>
#include <vector>
using namespace std;

bool f[200005];
int n,m,ans;
bool da;
vector <int> v[100005];
void dfs(int nod)
{
    f[nod]=1;
    for(int i=0;i<v[nod].size();++i)
    {
        if(f[v[nod][i]]==0)
            dfs(v[nod][i]);
    }
}
//ifstream cin("dfs.in");
//ofstream cout("dfs.out");
int main()
{   int a,b;
    cin>>n>>m;
    for(int i=1;i<=m;++i)
    {

        cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;++i)
    {
        if(f[i]==0)
            ++ans,dfs(i);
    }
    cout<<ans;
    return 0;
}