#include <cstdio>
#include <vector>
using namespace std;
vector<int> v[100007];
char vaz[100007];
void dfs(int nod)
{
    vaz[nod]=1;
    for(int i=0;i<v[nod].size();i++)
        if(!vaz[v[nod][i]]) dfs(v[nod][i]);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,x,y,nr=0;
    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])
        {
            nr++;
            dfs(i);
        }
    printf("%d",nr);
    return 0;
}