2889.Geometrical problem

Time Limit: 1s Memory Limit: 256MB

Polycarp loves geometric progressions - he collects them. However, as such progressions occur very rarely, he also loves the sequences of numbers where it is enough to delete a single element to get a geometric progression.

In this task we shall define geometric progressions as finite sequences of numbers a1,a2,...,ak, where ai=c \cdot bi-1 for some real numbers c and b. For example, the sequences [2, -4, 8], [0, 0, 0, 0], [199] are geometric progressions and [0, 1, 2, 3] is not.

Recently Polycarp has found a sequence and he can't classify it. Help him to do it. Determine whether it is a geometric progression. If it is not, check if it can become a geometric progression if an element is deleted from it.

Input Format(From the terminal/stdin)

The first line contains an integer n (1 \le n \le 105) - the number of elements in the given sequence. The second line contains the given sequence. The numbers are space-separated. All the elements of the given sequence are integers and their absolute value does not exceed 104.

Output Format(To the terminal/stdout)

Print 0, if the given sequence is a geometric progression. Otherwise, check if it is possible to make the sequence a geometric progression by deleting a single element. If it is possible, print 1. If it is impossible, print 2.

Sample Input 1

Copy
4
3 6 12 24
 \n
 · ·  ·  \n

Sample Output 1

Copy
0
 \n

Sample Input 2

Copy
4
-8 -16 24 -32
 \n
  ·   ·  ·   \n

Sample Output 2

Copy
1
 \n

Sample Input 3

Copy
4
0 1 2 3
 \n
 · · · \n

Sample Output 3

Copy
2
 \n

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