#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline T S(T a) {
  return a * a;
}
template <class T>
inline string tostring(T a) {
  ostringstream os("");
  os << a;
  return os.str();
}
template <typename T>
inline long long tolong(T a) {
  long long res;
  istringstream os(a);
  os >> res;
  return res;
}
template <typename T>
inline T gcd(T a, T b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
template <typename T>
inline T bigmod(T a, T b, T m) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return S(bigmod(a, b / 2, m)) % m;
  else
    return (a % m * bigmod(a, b - 1, m)) % m;
}
const int inf = (int)1e9 + 5;
const long long linf = (long long)1e16 + 5;
const long long modd = (long long)1e9 + 7;
const int mod = 10000007;
void pr(int f) {
  if (f == 1)
    cout << "YES\n";
  else
    cout << "NO\n";
}
bool isprime(long long n) {
  if (n < 2) return 0;
  if (n == 2)
    return 1;
  else {
    for (int i = 2; i * i <= n; i++)
      if (n % i == 0) return 0;
  }
  return 1;
}
long long countSum(long long x) {
  long long res = 0;
  while (x != 0) {
    res += (x % 10);
    x /= 10;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(0);
  int t;
  cin >> t;
  while (t--) {
    long long a, b, k, l, m, n, x, y, ans, sum, r;
    cin >> a >> b;
    if (a % 2 == 1) {
      if ((a * 2) <= b) {
        cout << a << " " << (a * 2) << endl;
      } else
        cout << -1 << " " << -1 << endl;
    } else {
      if (a * 2 <= b) {
        cout << a << " " << a * 2 << endl;
      } else
        cout << -1 << " " << -1 << endl;
    }
  }
}

### Prompt

Develop a solution in Cpp to the problem described below:

Let LCM(x, y) be the minimum positive integer that is divisible by both x and y. For example, LCM(13, 37) = 481, LCM(9, 6) = 18.

You are given two integers l and r. Find two integers x and y such that l ≤ x < y ≤ r and l ≤ LCM(x, y) ≤ r.

Input

The first line contains one integer t (1 ≤ t ≤ 10000) — the number of test cases.

Each test case is represented by one line containing two integers l and r (1 ≤ l < r ≤ 10^9).

Output

For each test case, print two integers:

  * if it is impossible to find integers x and y meeting the constraints in the statement, print two integers equal to -1; 
  * otherwise, print the values of x and y (if there are multiple valid answers, you may print any of them). 

Example

Input


4
1 1337
13 69
2 4
88 89


Output


6 7
14 21
2 4
-1 -1

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline T S(T a) {
  return a * a;
}
template <class T>
inline string tostring(T a) {
  ostringstream os("");
  os << a;
  return os.str();
}
template <typename T>
inline long long tolong(T a) {
  long long res;
  istringstream os(a);
  os >> res;
  return res;
}
template <typename T>
inline T gcd(T a, T b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
template <typename T>
inline T bigmod(T a, T b, T m) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return S(bigmod(a, b / 2, m)) % m;
  else
    return (a % m * bigmod(a, b - 1, m)) % m;
}
const int inf = (int)1e9 + 5;
const long long linf = (long long)1e16 + 5;
const long long modd = (long long)1e9 + 7;
const int mod = 10000007;
void pr(int f) {
  if (f == 1)
    cout << "YES\n";
  else
    cout << "NO\n";
}
bool isprime(long long n) {
  if (n < 2) return 0;
  if (n == 2)
    return 1;
  else {
    for (int i = 2; i * i <= n; i++)
      if (n % i == 0) return 0;
  }
  return 1;
}
long long countSum(long long x) {
  long long res = 0;
  while (x != 0) {
    res += (x % 10);
    x /= 10;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(0);
  int t;
  cin >> t;
  while (t--) {
    long long a, b, k, l, m, n, x, y, ans, sum, r;
    cin >> a >> b;
    if (a % 2 == 1) {
      if ((a * 2) <= b) {
        cout << a << " " << (a * 2) << endl;
      } else
        cout << -1 << " " << -1 << endl;
    } else {
      if (a * 2 <= b) {
        cout << a << " " << a * 2 << endl;
      } else
        cout << -1 << " " << -1 << endl;
    }
  }
}

```