Seven boxes, C, H, A, I, R, E and D, are kept one over the other but not necessarily in the same order. Only three boxes are kept above C. Only one box is kept between D and C. Only three boxes are kept between D and A. A is kept at some place above C. I is kept immediately below A. H is kept at one of the places above E. R is not kept immediately above or below D. Which box is kept at the lowermost position?