#include <fstream>
#include <vector>
#define DIM 100010
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m, i, v[DIM], nr;
vector<int> L[DIM];

void dfs(int x){
    v[x]=1;
    //caut primul element nevizitat din lista lui x
    for(int i=0; i<L[x].size(); i++)
        if(v[ L[x][i] ]==0)
            dfs(L[x][i]);
}

int main(){
    int x, y;
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1; i<=n; i++)
        if(v[i]==0)
        {
            dfs(i);
            nr++;
        }
    g<<nr<<"\n";
    return 0;
}