Get Tile Set Number of Tiles?

[11clock]

Hello, I am making a script that places down random tiles in a specific tile layer. But I cannot figure out how to get the number of tiles in a tile layer's tile set. How do you obtain this information?

Here is the code context.

var lay = layer_get_id("Ground")

if lay != -1 {
var map = layer_tilemap_get_id(lay)

var map_width = tilemap_get_width(map)
var map_height = tilemap_get_height(map)
var set = tilemap_get_tileset(map)

for (var row = 0; row < map_height; row++) {
for (var col = 0; col < map_width; col++) {
tilemap_set(map, irandom_range(1, /*whatever you do to get tile set tile number*/), col, row)
}
}
}