#P1407D. Discrete Centrifugal Jumps

    ID: 1257 Type: RemoteJudge 2000ms 256MiB Tried: 0 Accepted: 0 Difficulty: (None) Uploaded By: Tags>data structuresdpgraphs*2200

Discrete Centrifugal Jumps

No submission language available for this problem.

Description

There are nn beautiful skyscrapers in New York, the height of the ii-th one is hih_i. Today some villains have set on fire first n1n - 1 of them, and now the only safety building is nn-th skyscraper.

Let's call a jump from ii-th skyscraper to jj-th (i<ji < j) discrete, if all skyscrapers between are strictly lower or higher than both of them. Formally, jump is discrete, if i<ji < j and one of the following conditions satisfied:

  • i+1=ji + 1 = j
  • max(hi+1,,hj1)<min(hi,hj)\max(h_{i + 1}, \ldots, h_{j - 1}) < \min(h_i, h_j)
  • max(hi,hj)<min(hi+1,,hj1)\max(h_i, h_j) < \min(h_{i + 1}, \ldots, h_{j - 1}).

At the moment, Vasya is staying on the first skyscraper and wants to live a little longer, so his goal is to reach nn-th skyscraper with minimal count of discrete jumps. Help him with calcualting this number.

The first line contains a single integer nn (2n31052 \le n \le 3 \cdot 10^5) — total amount of skyscrapers.

The second line contains nn integers h1,h2,,hnh_1, h_2, \ldots, h_n (1hi1091 \le h_i \le 10^9) — heights of skyscrapers.

Print single number kk — minimal amount of discrete jumps. We can show that an answer always exists.

Input

The first line contains a single integer nn (2n31052 \le n \le 3 \cdot 10^5) — total amount of skyscrapers.

The second line contains nn integers h1,h2,,hnh_1, h_2, \ldots, h_n (1hi1091 \le h_i \le 10^9) — heights of skyscrapers.

Output

Print single number kk — minimal amount of discrete jumps. We can show that an answer always exists.

Samples

Sample Input 1

5
1 3 1 4 5

Sample Output 1

3

Sample Input 2

4
4 2 2 4

Sample Output 2

1

Sample Input 3

2
1 1

Sample Output 3

1

Sample Input 4

5
100 1 100 1 100

Sample Output 4

2

Note

In the first testcase, Vasya can jump in the following way: 12451 \rightarrow 2 \rightarrow 4 \rightarrow 5.

In the second and third testcases, we can reach last skyscraper in one jump.

Sequence of jumps in the fourth testcase: 1351 \rightarrow 3 \rightarrow 5.