#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
int s=0,n,m,x,y,i,nr,maxi=-609,benis,a,b,b1,b2,visitat[100001];
vector<int>v[100001];
void filix(int x)
{
    visitat[x]=1;
    for(int j=0; j<v[x].size();j++)
    {
        if(visitat[v[x][j]]==0)
        {
           //cout<<x<<' ';
            filix(v[x][j]);
        }
    }
}
int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    in>>n>>m;
    for(i=1; i<=m; i++)
    {
        in>>a>>b;
        v[b].push_back(a);
        v[a].push_back(b);
    }
    for(i=1; i<=n; i++)
    {
        if(visitat[i]==0)
        {
            filix(i);
            s++;
        }
    }
    out<<s<<' ';
    return 0;
}
//adiacenta