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