Let's note the vaults 1, 2, 3, 4.

Day 1: Visit vault 2 Day 2: Visit vault 2 Day 3: Visit vault 3 Day 4: Visit vault 3 Day 5: Visit vault 2

## Maximum 5 days?

Let's note the vaults 1, 2, 3, 4.

Day 1: Visit vault 2

Day 2: Visit vault 2

Day 3: Visit vault 3

Day 4: Visit vault 3

Day 5: Visit vault 2