Returns the least integer greater than or equal to its argument.
Elemental function
The result has a value equal to the least integer greater than or equal to A.
The result is undefined if the result cannot be represented as an integer of the specified KIND.
CEILING(-3.7) has the value -3.
CEILING(3.7) has the value 4.
CEILING(1000.1, KIND=2) has the value 1001, with a kind
type parameter of two.