nth Term
Easy
13
5.9% Acceptance
Task

There is a series, S , where the next term is the sum of pervious three terms. Given the first three terms of the series, a ,b ,c and respectively, you have to output the nth term of the series.

S(n) = a for n=1
S(n) = b for n=2
S(n) = c for n=3
S(n) = S(n1) + S(n2) + S(n3) for n>3

Create a function nthTerm(uint n, uint a, uint b, uint c) where n is the nth term to find and a,b,c are the three terms of the series.
For Example  If n=5 a=1 b=2 c=3 then nthTerm() must return 11 as
S(1) = 1
S(2) = 2
S(3) = 3
S(4) = S(3) + S(2) + S(1) = 1+2+3 = 6
S(5) = S(4) + S(3) + S(2) = 6 + 3 + 2 = 11
Note  Function will be public.
You can do this :)