#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#define MAXN 100010

long *G[MAXN], deg[MAXN], n, m, sol, sel[MAXN], Y2, Y1, i;

void read() {
	long Y1 = 0, Y2 = 0;
	scanf("%ld %ld", &n, &m);
	for (long i = 1; i <= m; ++i) {
		scanf("%ld %ld", &Y1, &Y2);
		++deg[Y1];
		++deg[Y2];
	}
}

void DFS(long Y1) {
	for (long i = 0; i < deg[Y1]; ++i) {
		if (!sel[G[Y1][i]]) {
			sel[G[Y1][i]] = 1;
			DFS(G[Y1][i]);
		}
	}
}

int main() {
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	
	read(); //gradele
	for (i = 1; i <= n; ++i) {
		G[i] = new long[deg[i]];
	}
	fclose(stdin);
	
	memset(deg, 0, sizeof(deg));
	
	freopen("dfs.in", "r", stdin);
	scanf("%ld %ld", &n, &m);
	for (i = 0; i < m; ++i) {
		scanf("%ld %ld", &Y1, &Y2);
		G[Y1][deg[Y1]++] = Y2;
		G[Y2][deg[Y2]++] = Y1;
	}
	for (i = 1; i <= n; ++i) {
		if (!sel[i]) {
			sel[i] = 1;
			DFS(i);
			++sol;
		}
	}
	
	printf("%ld\n", sol);
	for (i = 1; i <= n; ++i) {
		delete []G[i];
	}
	return 0;
}