// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(0.8);


const turtle = new Turtle();
let left = true;
let step = 0;


function isPrime(n){
	for(let i = 2; i <= Math.floor(Math.sqrt(n)); i++){
		if( n % i === 0){
			return false;
		}
	}
	return true;
}


function walk(i) {
    turtle.penup();
    turtle.goto(0, 0);
    turtle.pendown();
    turtle.setheading(i/10);
    for (let j = 0; j < 150; j++) {
        if (isPrime(i+step)) {
            if (left) {
                turtle.left(2);
            }
            else {
                turtle.right(2);
            }
            left = !left;
        }
        turtle.forward(1);
        step += 1;
    }
    return i < 3600;
}