human
Length of the smallest number which is divisible by K and formed by using 1 's only | Function to return length of the resultant number.
If K is a multiple of 2 or 5.
Generate all possible numbers 1 , 11 , 111 , 111 , ... , K 1 's.
If number is divisible by k then return the length.
Driver code"
Solution in Python:

Can you provide a code to length of the smallest number which is divisible by K and formed by using 1 's only and the other steps required?
assistant
#Here is code to length of the smallest number which is divisible by K and formed by using 1 's only and the other steps required.
 def numLen ( K ) :
	if ( K % 2 == 0 or K % 5 == 0 ) :
		return - 1 ;
	number = 0 ;
	len = 1 ;
	for len in range ( 1 , K + 1 ) :
		number = number * 10 + 1 ;
		if ( ( number % K == 0 ) ) :
			return len ;
	return - 1 ;
K = 7 ;
print ( numLen ( K ) ) ;