#include<cstdio>
#include<vector>

using namespace std;

vector<int> v[100010];
int n,m,x,y,c;
bool viz[100010];

int dfs(int nod)
{
    viz[nod]=1;
    while(!v[nod].empty())
    {
        int next=v[nod].back();
        if(viz[next]==0)
        {
            dfs(next);
        }
        v[nod].pop_back();
    }
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    scanf("%d %d",&n,&m);

    for(int i=1;i<=m;i++)
    {
        scanf("%d %d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }

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