#include <stdio.h>
#include <iostream>
#include <cstring>
#include <stdlib.h>
#include <time.h>
#include <bitset>
#include <string>
#include <vector>
#include <math.h>
#include <stack>
#include <queue>
#include <list>
#include <set>
#include <limits.h>
#include <algorithm>
#include <deque>
#define nmax 100010
#define mod 1999999973
using namespace std;
int n,m,i,j,x,y,nr=0;
vector <int> g[nmax];
bitset <nmax> fr;
void dfs(int x)
{
    fr[x]=1;
    for (int i=0;i<g[x].size();i++)
        if (fr[g[x][i]]==0) dfs(g[x][i]);
}
int main() {
freopen("dfs.in","r",stdin);
freopen("dfs.out","w",stdout);
scanf("%d %d",&n,&m);
for (i=1;i<=m;i++) {
    scanf("%d %d",&x,&y);
    g[x].push_back(y); g[y].push_back(x);
}
for (i=1;i<=n;i++)
   if (fr[i]==0) { nr++; dfs(i); }
printf("%d",nr);
return 0;
}