#include <bits/stdc++.h>

using namespace std;
vector<int> v[100001];
bool ok[100001];
int n,m,a,b,cnt;
void dfs(int nod)
{
    ok[nod]=true;
    for(int vec:v[nod])
    {
        if(!ok[vec])dfs(vec);
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    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(!ok[i])
        {
            cnt++;
            dfs(i);
        }
    }
    cout<<cnt;

    return 0;
}