Can you solve this riddle?

You fill the three gallon jug and then pour it into the five gallon jug. Then you fill it again and pour it in the five gallon jug, leaving one gallon in the three gallon jug. Then you pour out the five gallon jug, pour the one gallon from the three gallon jug into the five gallon jug, then you fill the three gallon jug, pour it into the five gallon jug, leaving four gallons in the five gallon jug.