p02596 AtCoder Beginner Contest 174 - Repsept
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
```python
n=int(input())
f=0
for i in range(n):
  f=f*10+7
  f%=n
  if f==0:
    print(i+1)
    break
else:print(-1)
```