def recursive_function(x, n): # 基础情况 if n == 0: return 1 elif n == 1: return x else: # 递归情况 return x * recursive_function(x, n - 1) + (1 - x) * recursive_function(x, n - 2) # 读取输入 x, n = map(float, input().split()) # 计算函数值并保留两位小数 result = round(recursive_function(x, n), 2) # 输出结果 print(result)