Takahashi loves the number 7 and multiples of K.

Where is the first occurrence of a multiple of K in the sequence $7,77,777,\ldots$? (Also see Output and Sample Input/Output below.)

If the sequence contains no multiples of K, print -1 instead.

Constraints

• $1 \leq K \leq 10^6$
• K is an integer.

Input

Input is given from Standard Input in the following format:

K

Output

Print an integer representing the position of the first occurrence of a multiple of K. (For example, if the first occurrence is the fourth element of the sequence, print 4.)

Examples

Input

101

Output

4

Input

2

Output

-1

Input

999983

Output

999982

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