#include <fstream>
#include <vector>
#define nmax 100000
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,viz[nmax+5];
vector<int> v[nmax+5];
void dfs(int k)
{
    viz[k]=1;
    for(int i=0;i<v[k].size();i++)
        if(!viz[v[k][i]])
        dfs(v[k][i]);
}
int main()
{
    int x,y,s=0;
    fin>>n>>m;
    while(fin>>x>>y)
    v[x].push_back(y),v[y].push_back(x);
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
            {s++;dfs(i);}
    }
    fout<<s;
    fin.close();
    fout.close();
    return 0;
}