#include <fstream>
#include <vector>
using namespace std;
ifstream in ("dfs.in");
ofstream out ("dfs.out");
const int N = 100000;
vector <int> v[N+5];
bool viz[N+5];
void dfs(int x)
{
    viz[x] = 1;
    for(int i=0; i<v[x].size(); i++)
    {
        int vecin = v[x][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    int n,m,i,x,y,con=0;
    in>>n>>m;
    for(i=1; i<=m; i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            con++;
            dfs(i);
        }
    }
    out<<con<<'\n';
    return 0;
}