#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m;
int ans,minn=9999;
int tot=1;
bool jud[10000001];
struct line{
    int head,tail;
}s[10000001];
bool graph[10001][10001];

void dfs(int x)
{
    jud[x] = 1;
    for(int i=1;i<=n;++i) 
	{
        if(graph[x][i] && !jud[i]) 
		{
            dfs(i);
        }
    }
}

signed main() 
{
    cin>>n>>m;
    for(int i=1;i<=m;++i) 
	{
        cin>>s[i].head>>s[i].tail;
        graph[s[i].head][s[i].tail] = 1;
        graph[s[i].tail][s[i].head] = 1;
    }
    
    int cnt = 0;
    for(int i=1;i<=n;++i) 
	{
        if(!jud[i]) 
		{
            dfs(i);
            cnt++;
        }
    }
    
    cout<<cnt;
    return 0;
}