#include <cstdio>
#include <vector>
using namespace std;
int n,m,x,y,i,nr,visited[100005];
vector <int> G[100005];
void dfs(int node)
{
    visited[node]=1;
    for (int i=0; i<G[node].size(); i++)
    {
        int crt=G[node][i];
        if (!visited[crt]) dfs(crt);
    }
}
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);
    }
    nr=0;
    for (i=1; i<=n; i++)
        if (!visited[i])
        {
            dfs(i);
            nr++;
        }
    printf("%d\n",nr);
    return 0;
}