#import<fstream>
#import<vector>
#import<algorithm>
#import<cstring>
#import<queue>
#import<unordered_set>
#import<string>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<vector<int>>a;
vector<bool>rez;
void dfs(int x)
{
    for(auto c:a[x])
    {
        if(!rez[c])
        {
            rez[c]=1;
            dfs(c);
        }
    }
}
main()
{
    int n,m;
    cin>>n>>m;
    a.resize(n+1);
    rez.resize(n+1);
    for(int i=0;i<m;i++)
    {
        int x,y;
        cin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int s=0;
    for(int i=1;i<=n;i++)
    {
        if(!rez[i])
        {
            s++;
            dfs(i);
        }
    }
    cout<<s;
}