#include <iostream>
using namespace std;

void dfs(int v){
	if (color[v] != 0) {
		return;
	}
	color[v]=1
	for (int i=0;i<n;i++){
		if (a[v][i]&&color[v]==0){
			dist[i] = dist[v]+1; dfs(i);
		}
	}
	color[v]=z;
}

int main(){

}