#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100001

using namespace std;

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

int n, m, ncc;
vector<int> L[NMAX];
bool uz[NMAX];

void dfs(int x);

int main()
{
    int x,y;
    
    fin>>n>>m;


    for(int i = 0; i < m; i++)
    {
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }

    for(int i = 1; i <= n; i++)
        if(!uz[i])
            ncc++, dfs(i);

    cout<<ncc;

    return 0;
}

void dfs(int x)
{
    uz[x] = 1;
    for(int i = 0; i < L[x].size(); i++)
        if(L[x][i] && !uz[L[x][i]])
            dfs(L[x][i]);
}