#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int NMAX=100005;
int n,m,x,y,no_cc;
vector<vector<int>>graph;
bitset<NMAX>used;
void dfs(int node)
{
    used[node]=1;
    for(int next:graph[node])
        if(!used[next])
            dfs(next);
}
int main()
{
    f>>n>>m;
    graph.assign(n+1,vector<int>());
    for(int i=1; i<=m; i++)
    {
        f>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!used[i])
        {
            no_cc++;
            dfs(i);
        }
    g<<no_cc;
    return 0;
}