#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct vertex {
	int name;
	struct vertex* next;
} vertex;

typedef struct graphVertex {
	int numNodes;
	int numEdges;
	vertex** nodes;
} graphVertex;

void legare_noduri_lista(vertex** listStart, int value)
{
	vertex* nou;
	nou = malloc(sizeof(vertex*));
	nou->name = value;
	nou->next = *listStart;
	*listStart = nou;
}

void dfs_vertex(graphVertex graph, int currentNode, int* visited)
{
	vertex* listStart;
	visited[currentNode] = 1;
	for (listStart = graph.nodes[currentNode]; listStart != NULL; listStart = listStart->next)
		if (!visited[listStart->name]) {
			dfs_vertex(graph, listStart->name, visited);
		}
}

graphVertex initializare(const char* fileName)
{
	graphVertex graph;
	graph.numEdges = 0;
	graph.numNodes = 0;
	int node1, node2;
	FILE* f = fopen(fileName, "r");
	if (f == NULL)
		return graph;

	fscanf(f, "%i%i", &(graph.numNodes), &(graph.numEdges));
	graph.nodes = (vertex**)malloc(sizeof(vertex*) * graph.numNodes);
	if (graph.nodes == NULL)
		return graph;
	for (int i = 0; i < graph.numEdges; i++) {
		fscanf(f, "%d %d", &node1, &node2);
		legare_noduri_lista(&graph.nodes[node1], node2);
		legare_noduri_lista(&graph.nodes[node2], node1);
	}
	fclose(f);
	return graph;
}
int main()
{
	FILE* fout;
	graphVertex graf = initializare("dfs.in");
	int* vizitat;
	int contor = 0;
	vizitat = calloc(0, sizeof(int) * graf.numNodes);
	for (int i = 0; i < graf.numNodes; i++) {
		if (!vizitat[i]) {
			dfs_vertex(graf, i, vizitat);
			contor++;
		}
	}
	fout = fopen("dfs.out", "w");
	fprintf(fout, "%d", contor);
	fclose(fout);
	return 0;
}