Question: what flag is blue and white with a cross?
Answer: The national flag of Greece, popularly referred to as the "blue and white" (Greek: Γαλανόλευκη, Galanólefki) or the "sky blue and white" (Κυανόλευκη, Kyanólefki), is officially recognised by Greece as one of its national symbols and has nine equal horizontal stripes of blue alternating with white.