def cost(ws): #输入数字数量，输出它对应费用 a = ws//70 * 0.1 if ws%70>0: a = a + 0.1 return a n = int(input()) res = 0 for x in range(n): words = int(input()) res += cost( words ) #函数调用 res = "{:.1f}".format(res) print(res)