n = int(input()) a,b,c,d = list(map(int,input().split())) flag =0 if b-a == c-b == d-c: flag = 1 if flag ==0:#等比数列 t = b/a res = a for i in range(n-1): res *= t else: t = b-a res = a for i in range(n-1): res += t print(int(res))