#include<fstream>
#include<algorithm>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int nlim =100005;

vector<int> a[nlim];
int v[nlim];
int n,m,k;
void dfs(int i)
{
    
    v[i] = 1;
    for(unsigned int j = 0; j<a[i].size(); ++j)
    {
        int vec = a[i][j];
        if(v[vec] == 0)
        {
            dfs(vec);
        }
    }
}
int main()
{
    f>>n>>m;
    for(int i =1; i<=m ; ++i)
    {
        int x,y;
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i =1;i<=n;i++)
    if(v[i]==0){
        k++;
        dfs(i);
    }
    g<<k;
    return 0;
}