#include<cstdio>
#include<vector>
using namespace std;

const char in[]="dfs.in";
const char out[]="dfs.out";

const int N = 100001;

vector<int> G[N];
int viz[N], n, m, sol;

void dfs(int x)
	{
		viz[x] = 1;
		for(unsigned int i = 0 ; i < G[x].size() ; ++i)
			if(!viz[G[x][i]]) dfs(G[x][i]);
}

int main()
	{
		freopen(in,"r",stdin);
		freopen(out,"w",stdout);
		
		scanf("%d%d", &n, &m);
		for(int i = 1 ; i <= m ; ++i)
		{
			int x, y;
			scanf("%d%d", &x, &y);
			G[x].push_back(y);
			G[y].push_back(x);
		}
		for(int i = 1 ; i <= n ; ++i)
			if(!viz[i])++sol, dfs(i);
		printf("%d\n", sol);
}