#include <bits/stdc++.h>
using namespace std;
vector <int> v[100001];
bool viz[100001];
void dfs(int nod)
{
    viz[nod]=1;
    for(auto it:v[nod])
        if(!viz[it])
            dfs(it);
}
int main()
{
#ifdef HOME
    freopen("test.in","r",stdin);
    freopen("test.out","w",stdout);
#endif // HOME
    int n,m,a,b,i,cnt=0;
    cin>>n>>m;
    for(i=1; i<=m; i++)
    {
        cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(i=1; i<=n; i++)
        if(!viz[i])
        {
            dfs(i);
            cnt++;
        }
    cout<<cnt;
    return 0;
}