Codeforces Round 783 (Div. 1) |
---|

Finished |

Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

brute force

greedy

math

*1300

No tag edit access

The problem statement has recently been changed. View the changes.

×
A. Make it Increasing

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputYou are given an array $$$a$$$ consisting of $$$n$$$ positive integers, and an array $$$b$$$, with length $$$n$$$. Initially $$$b_i=0$$$ for each $$$1 \leq i \leq n$$$.

In one move you can choose an integer $$$i$$$ ($$$1 \leq i \leq n$$$), and add $$$a_i$$$ to $$$b_i$$$ or subtract $$$a_i$$$ from $$$b_i$$$. What is the minimum number of moves needed to make $$$b$$$ increasing (that is, every element is strictly greater than every element before it)?

Input

The first line contains a single integer $$$n$$$ ($$$2 \leq n \leq 5000$$$).

The second line contains $$$n$$$ integers, $$$a_1$$$, $$$a_2$$$, ..., $$$a_n$$$ ($$$1 \leq a_i \leq 10^9$$$) — the elements of the array $$$a$$$.

Output

Print a single integer, the minimum number of moves to make $$$b$$$ increasing.

Examples

Input

5 1 2 3 4 5

Output

4

Input

7 1 2 1 2 1 2 1

Output

10

Input

8 1 8 2 7 3 6 4 5

Output

16

Note

Example $$$1$$$: you can subtract $$$a_1$$$ from $$$b_1$$$, and add $$$a_3$$$, $$$a_4$$$, and $$$a_5$$$ to $$$b_3$$$, $$$b_4$$$, and $$$b_5$$$ respectively. The final array will be [$$$-1$$$, $$$0$$$, $$$3$$$, $$$4$$$, $$$5$$$] after $$$4$$$ moves.

Example $$$2$$$: you can reach [$$$-3$$$, $$$-2$$$, $$$-1$$$, $$$0$$$, $$$1$$$, $$$2$$$, $$$3$$$] in $$$10$$$ moves.

Codeforces (c) Copyright 2010-2024 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Aug/03/2024 10:00:47 (h1).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|