[CrazY.]

#include <amxmodx>
#include <amxmisc>

public plugin_init()
{
    register_plugin("Plugin", "Version", "Author")

    new filename[128]
    formatex(filename[get_configsdir(filename, charsmax(filename))], charsmax(filename), "/numbers.txt")
    new file = fopen(filename, "r+t")
    new buffer[15]
    new num = 0

    if (fgets(file, buffer, charsmax(buffer)))
        num = str_to_num(buffer) + 1

    num_to_str(num, buffer, charsmax(buffer))
    fputs(file, buffer)

    fclose(file)
}