#D9450. 2
2
2
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.
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
inputFormat
Input
The only line of input contains three integers a1, a2, a3 (1 ≤ a1, a2, a3 ≤ 20), separated by spaces.
outputFormat
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
17 18 3
53