#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n,m,x,y,cnt;

bool vazut[1000005];
vector <int> a[10000005];

void dfs(int nod)
{
    vazut[nod]=1;
    for(auto i:a[nod])
    {
        if(!vazut[i])
        {
            vazut[i]=1;
            dfs(i);
        }
    }
}

int main()
{
    in>>n>>m;
    for(int i=0; i<m; ++i)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        if(!vazut[i])
        {
            dfs(i);
            cnt++;
        }
    }
    out<<cnt;
    return 0;
}