#include <bits/stdc++.h>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int N = 100010;
int n,m,c,i,j;
bitset<N> viz;
vector<int> v[N];
queue<int> q;
void bfs(int);
int main()
{
    f>>n>>m;
    for(; m; m--)
    {
        f>>i>>j;
        v[i].push_back(j);
        v[j].push_back(i);
    }
    for(i=1; i<=n; i++)
        if(!viz[i])
        {
            c++;
            bfs(i);
        }
    g<<c;
    return 0;
}
void bfs(int nod)
{
    q.push(nod);viz[nod]=1;
    while(q.size())
    {
        nod=q.front();
        q.pop();
        for(auto vec:v[nod])
        if(!viz[vec])
        {
            q.push(vec);viz[vec]=1;
        }
    }
}