#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int lim=1e5+4;
vector<int> vec[lim];
bool ok[lim];
void df(int nod)
{
    ok[nod]=true;
    for(int x:vec[nod])
    if(!ok[x]) df(x);
}
int main()
{
    int n,m,x,y;
    in>>n>>m;
    for(int i=1;i<=m;++i)
    {
        in>>x>>y;
        vec[x].push_back(y);
        vec[y].push_back(x);
    }
    int ans=0;
    for(int i=1;i<=n;++i)
    if(!ok[i]) ++ans,df(i);
    out<<ans<<'\n';
    return 0;
}