#include<cstdio>
#include<vector>
using namespace std;
vector<int> v[100001];
int n,m,i,viz[100001];
void dfs (int x)
{
    int y;
    viz[x]=true;
    for(size_t i=0; i<v[x].size();i++)
    {
        y=v[x][i];
        if(!viz[y])
            dfs(y);
    }
}
int main()
{
    int x,y;
    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);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int num=0;
    for(i=1;i<=n;i++)
        if(viz[i]==0)
            {
                num++;
                dfs(i);
            }
    printf("%d",num);
    return 0;
}