#include <cstdio>
#include <vector>

using namespace std;

vector<int> v[100010];
int vaz[100010];

void dfs(int nod)
{
    vaz[nod]=1;
    for(int i=0;i<v[nod].size();i++)
        if(vaz[v[nod][i]]==0) dfs(v[nod][i]);
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,r=0,x,y;
    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(vaz[i]==0)
        {
            r++;
            dfs(i);
        }
    printf("%d",r);
    return 0;
}