#include<stdio.h>
#include<vector>
using namespace std;
bool viz[100004];
int i,j,x,y,m,n,k;
vector <int> a[100001];
void dfs(int x)
{
    int i;
    viz[x]=1;
    for (i=0; i<a[x].size(); ++i)
        if (!viz[a[x][i]]) dfs(a[x][i]);
}

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);
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (i=1; i<=n ; ++i)
    if (viz[i]==0)
            {
                k++;
                dfs(i);
            }
    printf("%d",k);
    return 0;
}