#include <cstdio>
#include <vector>
using namespace std;

vector<int> g[100003];
int n,m;
bool u[100003];

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

int main()
{
    int i,rez=0,x,y;
    freopen("dfs.in","r",stdin);
    scanf("%d %d",&n,&m);
    for(;m;--m)
    {
        scanf("%d %d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    fclose(stdin);
    for(i=1;i<=n;++i)
    if(!u[i])
    {
        dfs(i);
        rez++;
    }
    freopen("dfs.out","w",stdout);
    printf("%d\n",rez);
    fclose(stdout);
    return 0;
}