Problem Analysis #9

Kanana-2-30B-Thinking-2601 · Run 1

146.22s
26,916 toks
Problem Statement

On a circle are placed nonnegative real numbers

$$\nwith indices taken modulo $n$ (so $x_{n+1}=x_1$, $x_{n+2}=x_2$, etc.).\nThey satisfy the local constraint $$\nx_i + x_{i+1} + x_{i+2} \le 1 \qquad\text{for all } i=1,2,\dots,n.

\nFor such a configuration define

$$\nLet $M_n$ be the maximal possible value of $S$ over all admissible configurations $(x_1,\dots,x_n)$ satisfying the above condition. \nIt can be shown that for each positive integer $n$, the maximum $M_n$ is a rational number.\nFor the specific case $n=2026$, write $$\nM_{2026} \;=\; \frac{p}{q} $$\nin lowest terms, where $p$ and $q$ are coprime positive integers. \nDetermine the integer $p+q$.
Ground Truth
1017
Execution Trace
Reasoning Process

The maximum value MnM_n for n=2026n = 2026 is achieved with a periodic pattern where xi=0.5x_i = 0.5 if ii is odd and xi=0x_i = 0 if ii is even, which satisfies the local constraint xi+xi+1+xi+21x_i + x_{i+1} + x_{i+2} \leq 1 for all ii. This configuration gives:

S=i=1nxixi+2=n8S = \sum_{i=1}^{n} x_i x_{i+2} = \frac{n}{8}

for even nn. Substituting n=2026n = 2026:

M2026=20268=10134M_{2026} = \frac{2026}{8} = \frac{1013}{4}

The fraction 10134\frac{1013}{4} is in lowest terms since 1013 and 4 are coprime (1013 is odd and not divisible by 2). Thus, p=1013p = 1013 and q=4q = 4, and:

p+q=1013+4=1017p + q = 1013 + 4 = 1017

1017\boxed{1017}

Reasoning Process

[THOUGHT] We are to compute M_{2026} for the given problem. The maximum S is achieved with a periodic pattern and equals 2026/8. We will use Python to compute the reduced fraction and then output p+q. [/THOUGHT] [PYTHON] from math import gcd

n = 2026 numerator = n denominator = 8

g = gcd(numerator, denominator) p = numerator // g q = denominator // g print(p + q) [/PYTHON]

Tool Output
[PYTHON OUTPUT] 1017 [/PYTHON OUTPUT]
Reasoning Process

1017\boxed{1017}

Final Model Output
1017

Comparative Analysis (P9) (Average across runs)

Avg Time Taken

K-EXAONE-236B-A23B
1477.6
Solar-Open-100B
279.6
Gemini-3-Pro-Preview
178.1
Kanana-2-30B-Thinking-2601
106.0
Kanana-2-30B-Thinking
104.4
GPT-5.2 (high)
60.1
GLM-4.5-Air
51.7
HCX-007
40.2
Solar-Pro 2
32.8
EXAONE-4.0-32B
5.9

Avg Token Usage

K-EXAONE-236B-A23B
31533.3
Solar-Open-100B
29943.0
Gemini-3-Pro-Preview
28144.3
Kanana-2-30B-Thinking-2601
20830.7
Kanana-2-30B-Thinking
17433.0
GLM-4.5-Air
9787.3
Solar-Pro 2
8105.0
GPT-5.2 (high)
6624.7
HCX-007
5037.0
EXAONE-4.0-32B
4449.3