My name is Nth!
By Ricardo Martins, Instituto Federal do Sul de Minas Gerais 
Brazil
By Ricardo Martins, Instituto Federal do Sul de Minas Gerais Brazil
Nth was fascinated by numerical sequences. He practiced every day to discover new terms of a given sequence, given its initial values, but it took a lot of time to do this. So he needs you to help him by making an algorithm that calculates the nth term of a sequence, given the first three terms of it.
The input consists of several test cases. Each case contains four integer values, the first three being the initial values of a sequence, A, B and C; and the last value is about the nth term to be discovered in this sequence, N.
For each test case, print the nth term of the sequence.
| Input Samples | Output Samples |
|
1 2 3 10000 |
10000 |
|
11 20 29 6 |
56 |