We have derived a scheme for retrieving the primary reflections from the acoustic surface-reflection response by eliminating the free-surface and internal multiple reflections in one step. This scheme does not require model information and adaptive subtraction. It consists only of the reflection response as a correlation and convolution operator that acts on an intermediate wavefield from which we compute and capture the primary reflections. For each time instant, we keep one value for each source-receiver pair and store it in the new data set. The resulting data set contains only primary reflections, and from this data set, a better velocity model can be built than from the original data set. A conventional migration scheme can then be used to compute an artifact-free image of the medium. We evaluated the success of the method with a 2D numerical example. The method can have a wide range of applications in 3D strongly scattering media that are accessible from one side only.