#include <cstdio>
#include <vector>
#define IN "dfs.in","r",stdin
#define OUT "dfs.out","w",stdout
#define MAX 200010

using namespace std;

vector <int> gr[MAX];
int n,m;
bool v[MAX/2];

void dfs(int nod);

int main()
{
    freopen(IN);
    freopen(OUT);
    int x,y,cnt=0;
    scanf("%d%d",&n,&m);
    for(register int i=1;i<=m;i++){
        scanf("%d%d",&x,&y);
        gr[x].push_back(y);
        gr[y].push_back(x);
    }
    for(register int i=1;i<=n;i++)
        if(!v[i]){
            cnt++;
            dfs(i);
        }
    printf("%d",cnt);
    return 0;
}

void dfs(int nod){
    v[nod]=1;
    for(register int i=0;i<gr[nod].size();i++)
        if(!v[gr[nod][i]])
            dfs(gr[nod][i]);
}