#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;

vector <int> v[100010];
int n,m,nr;
int viz[100010];


void citire()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    int x,y;
    for(int i=0;i<m;i++)
    {
        scanf("%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

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

int main()
{
    citire();
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
        {
           dfs(i);
           nr++;
        }
    printf("%d",nr);


    return 0;
}