#include <fstream>
#define DIM 100002
using namespace std;

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

int n,m,x,y, a[DIM][DIM], comp;
bool viz[DIM];

void dfs(int nod){
    viz[nod]==1;
        for(int i=1;i<=n;i++){
            if(a[nod][i]==1){
                dfs(i);
            }
        }
}


int main()
{
    in>>n>>m;
    for(int i=1; i<=m;i++){
        in>>x>>y;
        a[x][y]=1;
        a[y][x]=1;
    }
    for(int i=1;i<=n;i++){
        if(viz[i]==0){
            dfs(i);
            comp++;
        }
    }
    out<<comp;

    return 0;
}