#include <fstream>
#include <vector>
using namespace std;
vector<int> L[100010];
int n,m,x,y,i,j,sol,v[100010];
void dfs(int crt){
    v[crt]=1;
    for (int i=0;i<L[crt].size();i++){
        int vec=L[crt][i];
        if (v[vec]==0){
            dfs(vec);
        }
    }
}
int main () {
    ifstream fin ("dfs.in");
    ofstream fout("dfs.out");
    fin>>n>>m;
    while(fin>>x>>y){
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for (i=1;i<=n;i++)
        if (v[i]==0){
            dfs(i);
            sol++;
        }
    fout<<sol;
    return 0;
}