#include <fstream>
#include <vector>
#include <queue>
#define NMAX 100005

using namespace std;

FILE* f=freopen("bfs.in","r",stdin);
FILE* o=freopen("bfs.out","w",stdout);

int n,m;
vector<int> graph[NMAX];
int visited[NMAX];

void DFS(int x)
{
    visited[x]=1;
    for(int i=0;i<graph[x].size();++i)
        if(!visited[graph[x][i]])
            DFS(graph[x][i]);
}

int main()
{
    scanf("%d%d",&n,&m);

    for(int i=0;i<m;++i)
    {
        int x,y;
        scanf("%d%d",&x,&y);

        graph[x].push_back(y);
        graph[y].push_back(x);
    }

    int count=0;

    for(int i=1;i<=n;++i)
    {
        if(!visited[i])
        {
            DFS(i);
            count+=1;
        }
    }

    printf("%d",count);

    return 0;
}