J. JavaScript
time limit per test
2 seconds
memory limit per test
1024 megabytes
input
standard input
output
standard output

JavaScript is one of the most important computer languages now. It is high-level and multi-paradigm. It supports functional and imperative programming styles. However, the ICPC World Finals does not offer JavaScript for problem solving.

JavaScript is considered as a weakly typed language. It sometimes implicitly converts values of one type into another type. For example, the minus operator (-) does not have any meaning on strings; it is defined to operate on numbers. When the minus operator is applied on two strings, JavaScript will convert the operands from strings into numbers and then apply the minus operation. That is why "2" + "2" - "2" evaluates to 20 in JavaScript. Moreover, JavaScript converts a string into NaN (Not-a-Number) if the string does not represent a number. If any operand of a minus operation is NaN, then the result of the operation must be NaN. For example, "a" + "2" is NaN.

Given two strings x and y, please write a program to compute the result of x - y in JavaScript.

Input

There is only one line containing two space-separated non-empty strings x and y.

  • $$$x$$$ and $$$y$$$ consist of only English letters and digits.
  • Both $$$x$$$ and $$$y$$$ have lengths less than 6.
  • If $$$x$$$ contains an English letter, then you may assume that JavaScript converts $$$x$$$ into NaN.
  • If $$$y$$$ contains an English letter, then you may assume that JavaScript converts $$$y$$$ into NaN.
  • You may assume that the result is not a number if it is not an integer.
Output

Print the result of the minus operation (x - y) on one Line. If the result is an integer, please print it without the decimal point. If the result is not a number, please print NaN.

Examples
Input
22 2
Output
20
Input
a 2
Output
NaN
Input
12345 x1y2z
Output
NaN