Problem Statement

There are $A$ slimes lining up in a row. Initially, the sizes of the slimes are all $1$.

Snuke can repeatedly perform the following operation.

• Choose a positive even number $M$. Then, select $M$ consecutive slimes and form $M / 2$ pairs from those slimes as follows: pair the $1$-st and $2$-nd of them from the left, the $3$-rd and $4$-th of them, $...$, the $(M-1)$-th and $M$-th of them. Combine each pair of slimes into one larger slime. Here, the size of a combined slime is the sum of the individual slimes before combination. The order of the $M / 2$ combined slimes remain the same as the $M / 2$ pairs of slimes before combination.

Snuke wants to get to the situation where there are exactly $N$ slimes, and the size of the $i$-th ($1 ≤ i ≤ N$) slime from the left is $a_i$. Find the minimum number of operations required to achieve his goal.

Note that $A$ is not directly given as input. Assume $A = a_1 + a_2 + ... + a_N$.

Constraints

• $1 ≤ N ≤ 10^5$
• $a_i$ is an integer.
• $1 ≤ a_i ≤ 10^9$

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Input

Input is given from Standard Input in the following format:

$N$ $a_1$ $a_2$ $...$ $a_N$

Output

Print the minimum number of operations required to achieve Snuke's goal.

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Sample Input 1

2
3 3

Sample Output 1

2

One way to achieve Snuke's goal is as follows. Here, the selected slimes are marked in bold.

• (1, 1, 1, 1, 1, 1) → (1, 2, 2, 1)
• (1, 2, 2, 1) → (3, 3)

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Sample Input 2

4
2 1 2 2

Sample Output 2

2

One way to achieve Snuke's goal is as follows.

• (1, 1, 1, 1, 1, 1, 1) → (2, 1, 1, 1, 1, 1)
• (2, 1, 1, 1, 1, 1) → (2, 1, 2, 2)

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Sample Input 3

1
1

Sample Output 3

0

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Sample Input 4

10
3 1 4 1 5 9 2 6 5 3

Sample Output 4

10