TIS-100 Bench: Undecimal Twin Rounder

SPEC44149538 Hard Arithmetic construction Routing & synchronization Community tournament puzzle · TIS-100 Bench report →

Round a value to the nearest multiples of N and 11−N, with ties rounded down. Two related outputs must share limited arithmetic resources.

In TIS-100 Bench, 16 LLMs each had one attempt at this TIS-100 puzzle, with 45 minutes to find a working program and keep improving it, without seeing the community leaderboard. 12 of 16 models solved it. Together they found 15 new Pareto-frontier points beyond the community leaderboard.

12 / 16models solved it
1,918best LLM cycles (2,694 community)
15new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles2,6941,918Opus 5.5 ★ New record
Nodes55GPT-6 Astra Ties record
Instructions2838Gemini 4 Argon · +36%

Community records from the community leaderboard when we froze it. A record counts only after fresh-game replay and 100,000 passing random tests.

Pareto frontier

Pareto explorer

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Community leaderboardModel frontier pointNew frontier point
Select a point with the mouse or keyboard to inspect its scores and program.

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Every model

ModelSolvedBest cyclesBest nodesBest instructionsNew frontier points
01Opus 5.5Yes1,91865815
02Gemini 4 ArgonYes2,2675383
03GPT-6 AstraYes2,5615451
04GPT-6.1 SolYes2,234544—
05Fable 5.1Yes2,436659—
06Gemini 3.8 FlashYes3,554657—
07Sonnet 5.5Yes3,991651—
08Muse Wonder 1.0Yes5,900653—
09Kimi K3.1 ProYes5,946669—
10Muse Spark 1.3Yes6,431897—
11DeepSeek V4.1 FlashYes7,808669—
12GPT-6 LunaYes12,270892—
13GLM-5.3No————
14Grok 4.7No————
15Haiku 5.5No————
16MiMo-V2.6-ProNo————

Best scores can come from different programs. New frontier points are not matched or beaten on all three scores by any community program.

Best model programs

These programs are in TIS-100 save format and released under the MIT License. All of this puzzle’s model programs are on GitHub and Hugging Face.

Opus 5.5 Fewest cycles★ New frontier point

1,918 cycles · 8 nodes · 88 instructionsSPEC44149538.1918-8-88.txt on GitHub

Opus 5.5 program running on SPEC44149538 in TIS-100
Node 0
MOV RIGHT, ACC
JRO ACC
NOP
ADD 1
NOP
ADD 1
NOP
ADD 1
NOP
SUB 3
MOV ACC, RIGHT
ADD UP
MOV ACC, RIGHT
MOV ACC, DOWN
MOV RIGHT, DOWN
Node 1
MOV UP, ACC
SAV
SUB 1
MOV ACC, LEFT
NEG
ADD 10
MOV ACC, DOWN
MOV LEFT, ACC
NEG
ADD ACC
ADD 6
ADD LEFT
MOV ACC, DOWN
SWP
MOV ACC, LEFT
Node 2
MOV UP, DOWN
MOV UP, ACC
SAV
ADD ACC
ADD ACC
L: JRO DOWN
MOV ACC, DOWN
JMP L
SWP
N: MOV ACC, DOWN
M: JRO DOWN
JMP N
MOV DOWN, DOWN
Node 3
MOV UP, RIGHT
MOV UP, DOWN
Node 4
MOV LEFT, DOWN
Node 5
MOV UP, ACC
SAV
K: MOV 1, UP
SUB UP
JGZ K
MOV 3, UP
F: ADD UP
JGZ X
MOV 1, UP
JMP F
X: MOV 2, UP
MOV ACC, UP
SWP
SUB UP
MOV ACC, DOWN
Node 6
MOV UP, ACC
SAV
K: MOV 1, RIGHT
SUB RIGHT
JGZ K
MOV 3, RIGHT
F: ADD RIGHT
JGZ X
MOV 1, RIGHT
JMP F
X: MOV 2, RIGHT
MOV ACC, RIGHT
SWP
SUB RIGHT
MOV ACC, DOWN
Node 7
MOV UP, ACC
SAV
ADD ACC
ADD ACC
L: JRO LEFT
MOV ACC, LEFT
JMP L
SWP
N: MOV ACC, LEFT
M: JRO LEFT
JMP N
MOV LEFT, LEFT

Gemini 4 Argon Fewest nodes★ New frontier point

3,927 cycles · 5 nodes · 56 instructionsSPEC44149538.3927-5-56.txt on GitHub

Gemini 4 Argon program running on SPEC44149538 in TIS-100
Node 0
MOV UP, ACC
SAV
P: MOV ACC, DOWN
MOV RIGHT, ACC
ADD ACC
ADD ACC
C: MOV ACC, DOWN
JRO DOWN
MOV RIGHT, ACC
F: MOV ACC, DOWN
JRO DOWN
MOV ACC, DOWN
SWP
JGZ P
Node 1
MOV UP, ACC
NEG
MOV ACC, LEFT
MOV ACC, LEFT
NEG
SUB 11
MOV ACC, LEFT
MOV ACC, LEFT
Node 2
MOV UP, ACC
MOV ACC, DOWN
C: ADD UP
MOV -1, UP
JGZ C
SUB UP
MOV 1, UP
F: ADD UP
MOV -1, UP
JGZ F
MOV ACC, DOWN
MOV ACC, DOWN
MOV UP, DOWN
MOV 1, UP
MOV UP, DOWN
Node 5
MOV UP, ACC
SUB UP
SAV
MOV UP, ACC
ADD ACC
SUB UP
JGZ G
SWP
ADD UP
JMP O
G: MOV UP, NIL
SWP
O: MOV ACC, RIGHT
JRO RIGHT
MOV ACC, DOWN
Node 6
MOV LEFT, NIL
MOV 1, LEFT
MOV LEFT, DOWN
MOV -13, LEFT

Gemini 4 Argon Fewest instructions

5,748 cycles · 5 nodes · 38 instructionsSPEC44149538.5748-5-38.txt on GitHub

Gemini 4 Argon program running on SPEC44149538 in TIS-100
Node 0
MOV UP, ACC
SAV
P: MOV ACC, DOWN
MOV RIGHT, ACC
L: MOV ACC, DOWN
JRO DOWN
SUB ACC
MOV ACC, DOWN
SWP
JGZ P
Node 1
MOV UP, ACC
NEG
MOV ACC, LEFT
NEG
SUB 11
MOV ACC, LEFT
Node 2
MOV UP, ACC
MOV ACC, DOWN
L: ADD UP
MOV -1, UP
JGZ L
SAV
ADD ACC
SUB UP
JGZ G
MOV 2, UP
JMP O
G: MOV 1, UP
O: SWP
SUB UP
MOV ACC, DOWN
Node 5
MOV UP, ACC
SUB UP
MOV ACC, DOWN
MOV UP, ACC
SUB UP
MOV ACC, RIGHT
Node 6
MOV LEFT, DOWN