#include<cstdio>
#include<vector>
using namespace std;
vector <int> v[100005];

bool viz[100005];
int n,m;
void dfs(int x)
{
    viz[x]=1;
    for(vector <int>::iterator it=v[x].begin();it!=v[x].end();it++)
        if(viz[*it] == 0)
            dfs(*it);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int i,x,y;
    scanf("%d %d",&n,&m);
    int lc=0;
    for(int i=1;i<=m;i++)
    {
        scanf("%d %d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0)
        {
            lc++;
            dfs(i);
        }
    printf("%d\n",lc);
    return 0;
}