input - prompt for user input
input(message) gives the user the prompt in the text string and then waits for input from the keyboard. The input can be expression which is evaluated by evstr . If nothing but a carriage return is entered at the prompt input(message) returns an empty matrix
Invoked with two arguments, the output is a character string which is the expression entered at keyboard. If nothing but a carriage return is entered at the prompt input(message) returns a single white space " " .
//x=input("How many iterations?") //x=input("What is your name?","string")