#include<fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int nr,i,n,m,x,y,v[100100];
vector<int>l[100100];
void dfs(int x)
{
    v[x]=1;
    for(unsigned int i=0;i<l[x].size();++i)
    if(!v[l[x][i]])
    dfs(l[x][i]);
}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;++i)
    {
        f>>x>>y;
        l[x].push_back(y);
        l[y].push_back(x);
    }
    for(i=1;i<=n;++i)
    if(v[i]==0)
    dfs(i),++nr;
    g<<nr<<'\n';
    return 0;
}