For a single cycle Processor, how many clock cycles are required to execute the following code segment that clears a string of length 5 bytes ($a1=5) ?

Bzero :

beq $a1, $zero, End

Loop :

sb $zero, 0($a0) # sb store byte in memory

add $a0, $a0, 1

sub $a1, $a1, 1

bne $a1, $zero, Loop

End : jr $ra