```
#
# Author: Arpit Bhayani
# https://arpitbhayani.me
#
x = raw_input().split()
dp = {}
def fib(t1, t2, n):
if n == 1:
return t1
if n == 2:
return t2
t3 = dp.get(n)
if t3 is None:
t3 = fib(t1, t2, n-2) + fib(t1, t2, n-1) ** 2
dp[n] = t3
return t3
print fib(int(x[0]), int(x[1]), int(x[2]))
```