#include<iostream.h>
#include<fstream.h>

int A[200][200], v[100000], x, y, i, nc, n, m;
void df(int x, int k);

int main(){
	ifstream f("dfs.in");
	ofstream g("dfs.out");
	f>>n>>m;
	for(i=1; i<=m; i++){
		f>>x>>y;
		A[x][y] = A[y][x] = 1;
	}
	
	for(i=1; i<=n; i++){
		if(v[i] == 0){
			nc++;
			df(i, nc);
		}
	}
	
	g<<nc;
	
	return 0;
}

void df(int x, int k){
	int i;
	v[x] = k;
	for(i=1; i<=n; i++)
		if(A[x][i] == 1 && v[i] == 0)
			df(i, k);
}