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B3. Distinguish four 2-qubit states
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

You are given 2 qubits which are guaranteed to be in one of the four orthogonal states:

Your task is to perform necessary operations and measurements to figure out which state it was and to return the index of that state (0 for , 1 for etc.). The state of the qubits after the operations does not matter.

You have to implement an operation which takes an array of 2 qubits as an input and returns an integer.

Your code should have the following signature:

namespace Solution {
open Microsoft.Quantum.Primitive;
open Microsoft.Quantum.Canon;

operation Solve (qs : Qubit[]) : Int
{
body
{
// your code here
}
}
}