#include <fstream>
#include <vector>

using namespace std;
int n,m;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
bool f[100001];
vector<int>G[100001];
void dfs(int nod){
    f[nod]=1;
    for(auto x : G[nod])
        if(!f[x])
            dfs(x);
}
int main(){
    fin>>n>>m;
    while(m--){
        int x,y; fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int sol = 0;
    for(int i=1;i<=n;i++)
        if(!f[i])
            sol++,dfs(i);
    fout<<sol;

    return 0;
}