Study the following information carefully and answer the questions that follow.
A, B, C, D, E, F, G, H and I are nine houses, C is 2 km East of B. A is 1 km North of B and H is 2 km South of A. C is 1 km West of H while D is 3 km East of G and F is 2 km North of G. I is situated just in middle of B and C while E is just in middle of H and D.
Distance between E and I is