#include<bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int N,M,x,y;
bool viz[100001];
vector <int> G[100001];
void dfs(int nod){
    viz[nod]=1;
    for(int i=0;i<G[nod].size();++i)
        if(!viz[G[nod][i]])
            dfs(G[nod][i]);
}
int main()
{
    f>>N>>M;
    while(M--){
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    x=0;
    for(int i=1;i<=N;++i)
        if(!viz[i])
            ++x,dfs(i);
    g<<x;
    return 0;
}