fn rotate3(n: u32) -> u32 {
    return n % 100 * 10 + n / 100
}

fn circularPrime3(n: u32) -> Bool {
    let a: u32 = rotate3(n)
    let b: u32 = rotate3(a)
    return std.math.isPrimeU32(n) && std.math.isPrimeU32(a) && std.math.isPrimeU32(b)
}

pub fn main(world: World) -> Void raises {
    if circularPrime3(197) {
        check world.out.write("circular prime ok\n")
    }
}