The basic task is simple: givenNreal numbers, you are supposed to calculate their average. But what makes it complicated is that some of the input numbers might not be legal. Alegalinput is a real number in [−] and is accurate up to no more than 2 decimal places. When you calculate the average, those illegal numbers must not be counted in.

Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integerN(≤). ThenNnumbers are given in the next line, separated by one space.

Output Specification:

For each illegal input number, print in a lineERROR: X is not a legal numberwhereXis the input. Then finally print in a line the result:The average of K numbers is Y

Sample Input 1:

7
5 -3.2 aaa 9999 2.3.4 7.123 2.35

Sample Output 1:

ERROR: aaa is
 
 not a legal number
ERROR: 9999 is not a legal number
ERROR: 2.3.4 is not a legal number
ERROR: 7.123 is not a legal number
The average of 3 numbers is 1.38

Sample Input 2:

2
aaa -9999

Sample Output 2:

ERROR: aaa is not a legal number
ERROR: -9999 is not a legal number
The average of 0 numbers is Undefined