#include<bits/stdc++.h>
using namespace std;
int seen[100005],n,m,x,y,sol;
vector<int> v[100005];
void dfs(int nod)
{
    seen[nod]=1;
    for(vector<int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
    {
        if(!seen[*it]) dfs(*it);
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    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(!seen[i])
        {
            sol++;
            dfs(i);
        }
    }
    printf("%d\n",sol);
    return 0;
}