#include "std.alpha"

function entry: string2integer
function calc: integerXinteger2integer

calc(counter, result) := {
    
    if ( counter = 0 ) then {
        return result;
    } else {
        result := result * counter;
        counter := counter - 1;
        return calc(counter, result);
    }
}



entry (arg) := {
    [integer: result; integer: userInput]

    result := printC('E');
    result := printC('n');
    result := printC('t');
    result := printC('e');
    result := printC('r');
    result := printC(' ');
    result := printC('N');
    result := printC('u');
    result := printC('m');
    result := printC('b');
    result := printC('e');
    result := printC('r');
    result := printC(':');
    result := printC(' ');

    userInput := inI(1);
    userInput := calc(userInput, 1);
    result := printI(userInput);

    return 0;
}