part1 (4201B)
1--- Day 14: Space Stoichiometry --- 2 3As you approach the rings of Saturn, your ship's [1m[97mlow fuel[0m indicator turns on. There isn't any fuel 4here, but the rings have plenty of raw material. Perhaps your ship's Inter-Stellar Refinery Union 5brand [1m[97mnanofactory[0m can turn these raw materials into fuel. 6 7You ask the nanofactory to produce a list of the [1m[97mreactions[0m it can perform that are relevant to this 8process (your puzzle input). Every reaction turns some quantities of specific [1m[97minput chemicals[0m into 9some quantity of an [1m[97moutput chemical[0m. Almost every [1m[97mchemical[0m is produced by exactly one reaction; the 10only exception, ORE, is the raw material input to the entire process and is not produced by a 11reaction. 12 13You just need to know how much [1m[97mORE[0m you'll need to collect before you can produce one unit of 14[1m[97mFUEL[0m. 15 16Each reaction gives specific quantities for its inputs and output; reactions cannot be partially 17run, so only whole integer multiples of these quantities can be used. (It's okay to have leftover 18chemicals when you're done, though.) For example, the reaction 1 A, 2 B, 3 C => 2 D means that 19exactly 2 units of chemical D can be produced by consuming exactly 1 A, 2 B and 3 C. You can run 20the full reaction as many times as necessary; for example, you could produce 10 D by consuming 5 A, 2110 B, and 15 C. 22 23Suppose your nanofactory produces the following list of reactions: 24 2510 ORE => 10 A 261 ORE => 1 B 277 A, 1 B => 1 C 287 A, 1 C => 1 D 297 A, 1 D => 1 E 307 A, 1 E => 1 FUEL 31 32The first two reactions use only ORE as inputs; they indicate that you can produce as much of 33chemical A as you want (in increments of 10 units, each 10 costing 10 ORE) and as much of chemical B 34as you want (each costing 1 ORE). To produce 1 FUEL, a total of [1m[97m31[0m ORE is required: 1 ORE to 35produce 1 B, then 30 more ORE to produce the 7 + 7 + 7 + 7 = 28 A (with 2 extra A wasted) required 36in the reactions to convert the B into C, C into D, D into E, and finally E into FUEL. (30 A is 37produced because its reaction requires that it is created in increments of 10.) 38 39Or, suppose you have the following list of reactions: 40 419 ORE => 2 A 428 ORE => 3 B 437 ORE => 5 C 443 A, 4 B => 1 AB 455 B, 7 C => 1 BC 464 C, 1 A => 1 CA 472 AB, 3 BC, 4 CA => 1 FUEL 48 49The above list of reactions requires [1m[97m165[0m ORE to produce 1 FUEL: 50 51 52 - Consume 45 ORE to produce 10 A. 53 54 - Consume 64 ORE to produce 24 B. 55 56 - Consume 56 ORE to produce 40 C. 57 58 - Consume 6 A, 8 B to produce 2 AB. 59 60 - Consume 15 B, 21 C to produce 3 BC. 61 62 - Consume 16 C, 4 A to produce 4 CA. 63 64 - Consume 2 AB, 3 BC, 4 CA to produce 1 FUEL. 65 66 67Here are some larger examples: 68 69 70 - [1m[97m13312[0m ORE for 1 FUEL: 71 72157 ORE => 5 NZVS 73165 ORE => 6 DCFZ 7444 XJWVT, 5 KHKGT, 1 QDVJ, 29 NZVS, 9 GPVTF, 48 HKGWZ => 1 FUEL 7512 HKGWZ, 1 GPVTF, 8 PSHF => 9 QDVJ 76179 ORE => 7 PSHF 77177 ORE => 5 HKGWZ 787 DCFZ, 7 PSHF => 2 XJWVT 79165 ORE => 2 GPVTF 803 DCFZ, 7 NZVS, 5 HKGWZ, 10 PSHF => 8 KHKGT 81 82 83 - [1m[97m180697[0m ORE for 1 FUEL: 84 852 VPVL, 7 FWMGM, 2 CXFTF, 11 MNCFX => 1 STKFG 8617 NVRVD, 3 JNWZP => 8 VPVL 8753 STKFG, 6 MNCFX, 46 VJHF, 81 HVMC, 68 CXFTF, 25 GNMV => 1 FUEL 8822 VJHF, 37 MNCFX => 5 FWMGM 89139 ORE => 4 NVRVD 90144 ORE => 7 JNWZP 915 MNCFX, 7 RFSQX, 2 FWMGM, 2 VPVL, 19 CXFTF => 3 HVMC 925 VJHF, 7 MNCFX, 9 VPVL, 37 CXFTF => 6 GNMV 93145 ORE => 6 MNCFX 941 NVRVD => 8 CXFTF 951 VJHF, 6 MNCFX => 4 RFSQX 96176 ORE => 6 VJHF 97 98 99 - [1m[97m2210736[0m ORE for 1 FUEL: 100 101171 ORE => 8 CNZTR 1027 ZLQW, 3 BMBT, 9 XCVML, 26 XMNCP, 1 WPTQ, 2 MZWV, 1 RJRHP => 4 PLWSL 103114 ORE => 4 BHXH 10414 VRPVC => 6 BMBT 1056 BHXH, 18 KTJDG, 12 WPTQ, 7 PLWSL, 31 FHTLT, 37 ZDVW => 1 FUEL 1066 WPTQ, 2 BMBT, 8 ZLQW, 18 KTJDG, 1 XMNCP, 6 MZWV, 1 RJRHP => 6 FHTLT 10715 XDBXC, 2 LTCX, 1 VRPVC => 6 ZLQW 10813 WPTQ, 10 LTCX, 3 RJRHP, 14 XMNCP, 2 MZWV, 1 ZLQW => 1 ZDVW 1095 BMBT => 4 WPTQ 110189 ORE => 9 KTJDG 1111 MZWV, 17 XDBXC, 3 XCVML => 2 XMNCP 11212 VRPVC, 27 CNZTR => 2 XDBXC 11315 KTJDG, 12 BHXH => 5 XCVML 1143 BHXH, 2 VRPVC => 7 MZWV 115121 ORE => 7 VRPVC 1167 XCVML => 6 RJRHP 1175 BHXH, 4 VRPVC => 5 LTCX 118 119 120 121Given the list of reactions in your puzzle input, [1m[97mwhat is the minimum amount of ORE required to 122produce exactly 1 FUEL?[0m 123 124