Codeforces Round 565 A到E

//A 
#include <bits/stdc++.h>
#define ll long long 
using namespace std;
int main()
{
	ios::sync_with_stdio(false);
	int q;
	int ans,flag;
	ll tp;
	cin>>q;
	while(q--){
		cin>>tp;
		ans = 0; flag = 0;
		while(tp!=1){
			if(tp%2!=0&&tp%3!=0&&tp%5!=0){
			cout<<-1<<endl; flag = 1;
				break;
			}
			while(tp%2==0){
				tp/=2;
				ans++;
			}
			if(tp%3==0){
				tp=tp/3*2;
				ans++;
			}
			if(tp%5==0){
				tp=tp/5*4;
				ans++;
			}
		}
		if(!flag)cout<<ans<<endl;
	}	
	
	return 0;
}

//B
#include <bits/stdc++.h>
#define ll long long 
using namespace std;
int n,t,ans,m;
int a[101];
int b[101];
int main()
{
	cin>>t;
	while(t--){
		cin>>n;
		ans = 0;	b[1]=0; b[2]=0;
		int j=0;
		for(int i=0;i<n;i++){
			cin>>a[i];
			if(a[i]%3!=0){
				if(a[i]%3==1)b[1]++;
				else b[2]++;
			}else ans++; 
		}
		m = min(b[1],b[2]);
		if(b[1]>m)ans+=(b[1]-m)/3;
		if(b[2]>m)ans+=(b[2]-m)/3;
		cout<<ans+m<<endl;
	}
	
	return 0;
}

//C
#include <bits/stdc++.h>
#define ll long long 
using namespace std;
int a[500005];
int mp[101];
int cnt[7];
int n,m;
int main()
{
	cin>>n;
	mp[4] = 1;	mp[8] = 2; 	mp[15] = 3;
	mp[16] = 4;	mp[23] = 5;	mp[42] = 6;
	cnt[0] = 500005;
	int tp;
	for(int i=0;i<n;i++)
		{
			cin>>tp;
			tp = mp[tp];
			if(cnt[tp-1]){
				cnt[tp]++;	cnt[tp-1]--;
			}
		}

	cout<<n-cnt[6]*6<<endl;		
	return 0;	
}
/*
100
4 42 23 23 8 42 16 23 42 16 42 8 4 23 4 4 23 42 16 42 23 23 23 42 4 42 8 8 16 23 15 23 16 4 42 15 15 23 16 15 16 4 4 15 23 42 42 15 8 23 8 23 4 15 16 15 42 8 23 16 15 42 23 8 4 16 15 16 23 16 16 4 23 16 8 23 16 15 23 4 4 8 15 4 4 15 8 23 23 4 4 8 8 4 42 15 4 4 42 16

*/

//D 
#include <bits/stdc++.h>
#define ll long long 
using namespace std;
const int maxn = 2750131+10;
int n;
int prime[maxn+1],is_prime[maxn+1];
int low[maxn+1];
int mp[maxn+1];
multiset<int> q;
vector<int> ans;
void phi_prime() 
{	 
	memset(is_prime,0,sizeof(is_prime)); 
	for(int i=2;i<=2750131;i++){
		if(!is_prime[i])prime[++prime[0]]=i;	
		for(int j=1;j<=prime[0]&&i*prime[j]<=2750131;j++){
				is_prime[i*prime[j]] = 1;	low[i*prime[j]] = prime[j];
				if(i%prime[j]==0)break;	
		}
	}
	for(int i=1;i<=prime[0];i++){
		mp[prime[i]] = i;
	}
}

int main()
{
	int n,tp;
	phi_prime();

	cin>>n;
	q.clear();
	for(int i=0;i<2*n;i++){
		cin>>tp;
		q.insert(tp);
	}
	
	while(q.size()){
		int x = *q.rbegin();
		q.erase(--q.end());
		if(is_prime[x]){
			multiset<int>::iterator it = q.find(x/low[x]);
			ans.push_back(x);  q.erase(it);
		}else{
			multiset<int>::iterator it = q.find(mp[x]);
			ans.push_back(mp[x]);	q.erase(it);
		}
		
	}
	for(int i=0;i<ans.size();i++){
		cout<<ans[i]<<" \n"[i==ans.size()-1];
	}
	
	return 0;	
}

//E 
#include <bits/stdc++.h>
#define ll long long 
using namespace std;
const int maxn = 200005;

vector<int> ans,G[maxn];
int vis[maxn];
int n,m;
void dfs(int u,int fg){
	vis[u] = 1;
	if(fg) ans.push_back(u);
	for(int i=0;i<G[u].size();i++){
		int v = G[u][i];
		if(vis[v])continue;
		dfs(v,fg^1);
	} 
}
int main()
{
	cin.tie(0);
	int t,u,v;
	cin>>t;
	while(t--){
		cin>>n>>m;
		for(int i=1;i<=n;i++)G[i].clear(),vis[i]=0;
		ans.clear();
		
		for(int i=0;i<m;i++){
			cin>>u>>v;
			G[u].push_back(v);	G[v].push_back(u);	
		}
		dfs(1,0);
		if(ans.size()<=n/2){
			cout<<ans.size()<<endl;
			for(int i=0;i<ans.size();i++){
				cout<<ans[i]<<" \n"[i==ans.size()-1];
			}
		}else {
			ans.clear();
			for(int i=1;i<=n;i++)
				vis[i] = 0;
			dfs(1,1);
			cout<<ans.size()<<endl;
			for(int i=0;i<ans.size();i++){
				cout<<ans[i]<<" \n"[i==ans.size()-1];
			}
		}
	}

	return 0;	
}