#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i=0;i<n;i++)
#define all(v) v.begin(),v.end()
#define rall(v)v.rbegin(),v.rend()

using ll = long long;
using ull = unsigned long long;
#define iINF 2000000000
#define llINF 9000000000000000000ll
const int MOD9 = 998244353;
const int MOD1 = 1000000000 + 7;
const vector<int> dx = {0,1,0,-1} , dy = {1,0,-1,0};

//chmin , chmax
template<typename T>
bool chmin(T &a , T b){
    if(a > b){a = b ; return 1;}
    return 0;
}
template<typename T>
bool chmax(T &a , T b){
    if(a < b){a = b ; return 1;}
    return 0;
}

//io
template<typename T , typename F>
std::istream& operator>>(std::istream& is , pair<T,F> &p){
    is >> p.first >> p.second;
    return is;
}
template<typename T , typename F>
std::ostream& operator<<(std::ostream& os , const pair<T,F> &p){
    os << " [" << p.first << " : " << p.second << "] ";
    return os;
}

//vio
template<typename T>
void printv(vector<T> &v){
    rep(i,(int)v.size()){
        cout<<v[i];
        if(i+1 != (int)v.size()) cout<<" ";
    }
    cout<<endl;
}
template<typename T>
void printvv(vector<vector<T>> &vv){rep(i,(int)vv.size()) printv(vv[i]);}

template<typename T>
void printve(vector<T> &v){
    rep(i,(int)v.size()){
        cerr<<v[i];
        if(i+1 != (int)v.size()) cerr<<" ";
    }
    cerr<<endl;
}
template<typename T>
void printvve(vector<vector<T>> &vv){rep(i,(int)vv.size()) printve(vv[i]);}

template<typename T>
void vin(vector<T> &v){for(auto &vi : v) cin>>vi;}
template<typename T>
void vvin(vector<vector<T>> &vv){for(auto &vvi : vv) vin(vvi);}



int main(){cin.tie(0);ios::sync_with_stdio(0);
    int t;
    cin >> t;
    for(int i=0;i<t;i++){
        ll n , m;
        cin >> n >> m;
        //min((n - 2 * k) // 4 , (m + 4 * k) // 2)
        //(n - 2 * m) / 10 = k;
        ll K = (n - 2 * m) / 10ll;
        ll kmax = n / 2ll;
        ll ans = max(min(n / 4ll , m / 2ll) , min((n - 2 * kmax) / 4ll , (m + 4 * kmax) / 2ll));
        for(ll k = -100 + K ; k <= 100 + K ; k++){
            if(k < 0) continue;
            if(n - 2ll * k < 0) continue;
            
            chmax(ans , min((n - 2ll * k) / 4ll , (m + 4ll * k) / 2ll));
        }
        cout << 3ll * ans << endl;
    }
    
}