Codeforces Round 370 (Div. 2)
C
Memory and De-Evolution
Codeforces
1600
原题
← BD →
翻译中…

Memory is now interested in the de-evolution of objects, specifically triangles. He starts with an equilateral triangle of side length $*x*$, and he wishes to perform operations to obtain an equilateral triangle of side length $*y*$.

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In a single second, he can modify the length of a single side of the current triangle such that it remains a non-degenerate triangle (triangle of positive area). At any moment of time, the length of each side should be integer.

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What is the minimum number of seconds required for Memory to obtain the equilateral triangle of side length $*y*$?

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Input

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The first and only line contains two integers $*x*$ and $*y*$ ($3 ≤ *y* < *x* ≤ 100 000$) — the starting and ending equilateral triangle side lengths respectively.

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Output

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Print a single integer — the minimum number of seconds required for Memory to obtain the equilateral triangle of side length $*y*$ if he starts with the equilateral triangle of side length $*x*$.

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Note

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In the first sample test, Memory starts with an equilateral triangle of side length $6$ and wants one of side length $3$. Denote a triangle with sides $*a*$, $*b*$, and $*c*$ as $(*a*, *b*, *c*)$. Then, Memory can do image.

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In the second sample test, Memory can do image.

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In the third sample test, Memory can do: image

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image.

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样例

Input #1
6 3
Output #1
4
InputCopy OutputCopy
Input #2
8 5
Output #2
3
InputCopy OutputCopy
Input #3
22 4
Output #3
6
InputCopy OutputCopy
题目信息
题号
712C
时间限制
2 s
内存限制
256 MB
标签
贪心
数学

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