#include <bits/stdc++.h>

using namespace std;

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

int n,m,ans;
list<int>vecini[100010];
bool visited[100010];

void dfs(int x)
{
    visited[x] = 1;
    for(auto node : vecini[x])
    {
        if(!visited[node])
        {
            dfs(node);
        }
    }
}

int main()
{
    fin >>n >>m;
    while(m--)
    {
        int x,y;
        fin >>x >>y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }
    for(int i = 1;i <= n;i++)
    {
        if(!visited[i])
        {
           ans++;
           dfs(i);
        }
    }
    fout <<ans;
    return 0;
}