#include <bits/stdc++.h>

using namespace std;

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

vector<int> a[100001];
int d[100001] = {0};

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

int main()
{
    int N, M;
    in >> N >> M;
    for(int i = 1; i <= M; i++)
    {
        int x, y;
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int c = 0;
    for(int i = 1; i <= N; i++)
    {
        if(d[i] == 0)
        {
            dfs(i);
            c ++;
        }
    }
    out << c;
    return 0;
}