Circles cannot overlap (but may touch), centers must be integer, radius fixed at r. Only need ≥89% coverage, not all points. Points are uniformly random in a rectangle.

Use honeycomb (hexagonal) grid packing — the densest circle packing in plane. Map each point to nearest integer grid center as lattice point. Collect unique centers and output them.

Since circle area ≤ 1/10 of rectangle area, hex packing covers ~90.7% of plane. Integer rounding of centers is fine due to loose tolerance. No need to minimize circle count.