#include <iostream>
#include <fstream>
#include <vector>
#define lim 100005
using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

vector <int> v[lim];
int n, m, cate;
bool valid[lim];

void read()
{
    in>>n>>m;
    for(int i=1; i<=m; ++i)
    {
        int x, y;
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int x)
{
    valid[x]=1;
    for(int i=0; i<v[x].size(); ++i)
    {
        if(valid[v[x][i]]==0)
             dfs(v[x][i]);
    }
}

int main()
{
    read();
    for(int i=1; i<=n; ++i)
    {
        if(valid[i]==0)
        {
            ++cate;
            dfs(i);
        }
    }
    out<<cate;
    return 0;
}