#include <bits/stdc++.h>

using namespace std;
int n,m,x,y,cnt=0;
bool viz[100005]={0};
vector <int> adj[100005];
static void dfs(int nod){
viz[nod]=1;
for(auto x:adj[nod])
    if(!viz[x])
        dfs(x);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d ",&n,&m);
    while(m--){
        scanf("%d %d ",&x,&y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i])
            dfs(i),++cnt;
    printf("%d",cnt);
}