/**
* 广度优先
* @param {Graph}
* @return {void}
*/
void BFS (Graph G) {
if (G->kind == DG || G->kind == UDG) {
BFS1(G,0);
} else if (G->kind == DN || G->kind == UDN) {
BFS2(G,0);
}
}
int main(int argc, char* argv[])
{
Construct(argv[0]);
BFS1();
BFS2(argv[0]);
return 0;
}
int main()
{
//freopen("input.txt", "r", stdin);
char C[20];
gets(C);
int a,b;
if(sscanf(C,"%d %d",&a,&b) == 1)
{
int n = a, min_x = MAX, min_y = MAX, x, y;
bool visited[MAX][MAX];
for(x = 0; x < MAX; x++)
for(y = 0; y < MAX; y++)
visited[x][y] = true;
for(int i = 0; i < n; i++)
{
scanf("%d %d", &x, &y);
if(i == 0)
{
min_x = x;
min_y = y;
}
mas[x][y] = true;
visited[x][y] = false;
}
printf("%d %d\n", min_x, min_y);
BFS1(min_x, min_y,visited);
}
else
{
int x = a, y = b;
int count = BFS2(x,y);
printf("%d\n",count);
for(int x = 1; x < MAX; x++)
{
for(int y = 1; y < MAX; y++)
{
if(mas[x][y])
printf("%d %d\n",x,y);
}
}
}
return 0;
}
