No submission language available for this problem.

Description

Input

The only line of input contains three integers a₁, a₂, a₃ (1 ≤ a₁, a₂, a₃ ≤ 20), separated by spaces.

Output

Output a single integer.

Samples

2 3 2

5

13 14 1

14

14 5 9

464

17 18 3

53