### LANGUAGE: JAVA

### CHALLENGE:

NOTE: in mathematics, the square root of a negative number is not real; in Java therefore, passing such a value to the square root function returns a value known as NaN (not-a-number).

HOWEVER: if any value read in is not valid input, just print the message “INVALID”.

ASSUME the availability of a variable , stdin, that references a Scanner object associated with standard input.

### SOLUTION:

areaOfSquare = stdin.nextDouble(); if (areaOfSquare < 0) System.out.print("INVALID"); else System.out.print(Math.sqrt(areaOfSquare));