#include <iostream>
#include <vector>

using namespace std;

const int NMAX = 100002;
int n, m;

vector<vector<int>> a;
int viz[NMAX];

void fa(int inceput)
{
    viz[inceput] = 1;
    for(int con : a[inceput])
        if(!viz[con])
            fa(con);
}

int main()
{
    cin >> n >> m;
    for(int i=0; i<=n; i++)
        a.push_back(vector<int>());
    int x, y;
    for(int i=1; i<=m; i++) {
        cin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int r=0;
    for(int i=1; i<=n; i++) {
        if(viz[i])
            continue;
        fa(i);
        r++;
    }
    cout << r;
    return 0;
}