Generate a quantum program to roll a die of n faces.

def die_program(number_of_sides):
    """
    Generate a quantum program to roll a die of n faces.
    """
    prog = Program()
    n_qubits = qubits_needed(number_of_sides)
    ro = prog.declare('ro', 'BIT', n_qubits)
    # Hadamard initialize.
    for q in range(n_qubits):
        prog.inst(H(q))
    # Measure everything.
    for q in range(n_qubits):
        prog.measure(q, ro[q])
    return prog