A timber company uses a method of sustainable forestry to harvest wood from a managed forest.
Figure 1 shows a map of this managed forest, divided into 10 numbered sectors surrounding a central protected reserve of ancient woodland.
The harvesting rules are as follows:
- The trees are harvested in sequence: 1→2→3→4→5→6→7→8→9→101 \rightarrow 2 \rightarrow 3 \rightarrow 4 \rightarrow 5 \rightarrow 6 \rightarrow 7 \rightarrow 8 \rightarrow 9 \rightarrow 101→2→3→4→5→6→7→8→9→10.
- Trees are cut down in only one sector at any one time.
- It takes 24 years to complete the harvesting of trees in each single sector.
- The trees in the 'Protected reserve' are never cut down.
How many years will it take to complete one full harvesting cycle of all the numbered sectors?