#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
vector <int> a[100001];
int n,m;
bool viz[100001];
ifstream in("dfs.in");
ofstream out("dfs.out");
void dfs(int x)
{
    int y;
    viz[x]=true;
    for(unsigned i=0;i<a[x].size();i++)
    {
        y=a[x][i];
        if(!viz[y])
            dfs(y);
    }
}
int main()
{
    int x,y,j,nrc=0;
    in>>n>>m;
    for(j=0;j<m;j++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(j=1;j<=n;j++)
        if(!viz[j])
        {
            dfs(j);
            nrc++;
        }
    out<<nrc;
    return 0;
}