@paninid
- start with both jugs empty
- fill 3gal jug
- pour 3gal into 5gal jug
- fill 3gal
- pour 3gal into 5gal until it's full (leaving 1 gallon in 3gal)
- empty 5gal jug
- pour 3gal into 5gal
- fill 3gal
- pour 3gal into 5 gal
- 5gal jug now has 4 gallons