#include <vector>
#include <fstream>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int NMAX=100001;
vector<int> graf[NMAX];
bool visited[NMAX];
void dfs(int x)
{
    int y;
    visited[x]=1;
    for(int i=0; i<graf[x].size(); i++)
    {
        y=graf[x][i];
        if(!visited[y])
            dfs(y);
    }
}
int main()
{
    int n,m,x,y;
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    int nr=0;
    for(int i=1; i<=n; i++)
        if(!visited[i])
        {
            dfs(i);
            nr++;
        }
    out<<nr;


    return 0;
}