#include <bits/stdc++.h>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

const int N=100005;
int n,m,vis[N],c;
vector <int> v[N];

void dfs(int nod)
{
    vis[nod]=1;
    for(auto vec: v[nod])
        if(!vis[vec])
            dfs(vec);
}
int main()
{
    f>>n>>m;
    for(; m; m--)
    {
        int x,y;
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!vis[i])
        {
            c++;
            dfs(i);
        }
    g<<c;
    return 0;
}