#include <bits/stdc++.h>
using namespace std;
int m,n,i,nc,x,y;
bool sel[100010];
vector<int>g[100010];
void DFS(int x)
{
    int i;
    sel[x]=true;
    for(i=0; i<g[x].size(); ++i)
        if(!sel[g[x][i]])DFS(g[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);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(i=1; i<=n; ++i)
        if(!sel[i])
        {
            DFS(i);
            nc++;
        }
    printf("%d\n",nc);
    return 0;
}