#include <fstream>
#include <iostream>
#include <vector>
#include <deque>
#include <bitset>
#include <stack>
using namespace std;

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

vector<int> L[100010];
bitset<100010> v;

int n, m, i, j, x, y, sol;

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

int main () {
    fin>>n>>m;
    for (i=1;i<=m;i++) {
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }

    for (i=1;i<=n;i++)
        if (!v[i]) {
            sol++;
            dfs(i);
        }
    fout<<sol;
    return 0;
}