fn add(mut x : i32, y : i32) -> i32{
    println!("This is also in function add");
    x = x + x;
    x + y
}
fn print_twice(mut snake : str){
    println!("{}", snake);
    snake = "goose";
    println!("{}", snake);
}
/*
 * This is a comment
 */
fn main(){
    let z = add(100, 37);
    println!("Z = {}", z);

    if z == 137 {
        println!("Math works today!");
    }
    let s = "Python";
    print_twice(s);
    println!("s is now {}", s);
}