#include <bits/stdc++.h>
using namespace std;

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


vector<int> V[100005];
int n,m,x,y,ans;
bool viz[100005];

void dfs(int x){
    viz[x] = 1;
    for(int j = 0; j < V[x].size(); j++)
        if(viz[V[x][j]]== 0)
            dfs(V[x][j]);

}


int main(){
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        if(viz[i] == 0)
        {
            ans++;
            dfs(i);
        }

    fout << ans;


return 0;
}