haskell robot-name iteration 4

- remove superfluous do notation
- use mapM instead of sequence
haskell robot-name iteration 5

- desugar do notation
haskell grains iteration 2

- closed form solution for total
python accumulate iteration 1
python beer-song iteration 1
haskell gigasecond iteration 1
haskell triangle iteration 1
haskell triangle iteration 2

- triangles can't have sides <= 0
haskell scrabble-score iteration 1