#include <cstdio>
#include <vector>

using namespace std;
int n, m;
vector<vector<int> > v;
int DFS[100001];
void go(int nod) {
	if (DFS[nod]) return;
	DFS[nod] = 1;
	for (int i = 0; i < v[nod].size(); ++i) go(v[nod][i]);
}
int main() {
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	scanf("%d%d", &n, &m);	
	v.resize(n+3);
	while(m--) {
	int a, b;
	scanf("%d%d", &a, &b);
	v[a].push_back(b);
	v[b].push_back(a);
	}
int count = 0;
for (int i = 1; i <= n; ++i) if (DFS[i]==0) {++count; go(i);}
printf("%d\n", count);
return 0;
}