#include <bits/stdc++.h>

using namespace std;

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

vector<int> v[100001];
int parc[100001];

void dfs(int nod){
    int i;
    parc[nod]=1;
    for(i=0;i<v[nod].size();++i){
        int node = v[nod][i];
        if(parc[node]==0)
            dfs(node);
    }
}

int main()
{
    int n,m,x,y,i;
    in>>n>>m;
    for(i=1;i<=m;++i){
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int ans=0;
    for(i=1;i<=n;++i)
        if(parc[i]==0){
            ++ans;
            dfs(i);
        }
    out<<ans;
    return 0;
}