Mysterious numbers - 2
说明
G. Mysterious numbers - 2
time limit per test
2 secondsmemory limit per test
256 megabytesinput
standard inputoutput
standard outputInput
The only line of input contains three integers a1,a2,a3 (1≤a1,a2,a3≤20), separated by spaces.
Output
Output a single integer.
Examples
Input
2 3 2
Output
5
Input
13 14 1
Output
14
Input
14 5 9
Output
464
Input
17 18 3
Output
53
样例
