If a cell has 2n number of chromosomes in G1 phase, then what is the number of chromosomes in cell after S phase?

During S phase, the amount of DNA per cell doubles. If the initial amount of DNA is denoted as 2C then it increases to 4C. However, there is no increase in the chromosome number; if the cell had diploid or 2n number of chromosomes at G1, even after S phase the number of chromosomes remains the same, i.e., 2n.