{"raw_statement":[{"iden":"statement","content":"Bessie and Elsie are plotting to overthrow Farmer John at last! They plan it out\nover $N$ text messages. Their conversation can be\nrepresented by a string $S$ of length $N$ where $S_i$ is either `B` or `E`,\nmeaning the $i$ th message was sent by Bessie or Elsie, respectively. \n\nHowever, Farmer John hears of the plan and attempts to intercept their\nconversation. Thus, some letters of $S$ are `F`, meaning Farmer John obfuscated\nthe message and the sender is unknown.\n\nThe  **excitement level** of a non-obfuscated conversation is the number of\ntimes a cow double-sends - that is, the number of occurrences of substring `BB`\nor `EE` in $S$. You want to find the excitement level of the original message,\nbut you don’t know which of Farmer John’s messages were actually Bessie’s\n/ Elsie’s. Over all possibilities, output all possible excitement levels of\n$S$."},{"iden":"input","content":"The first line will consist of one integer $N$.\n\nThe next line contains $S$."},{"iden":"output","content":"First output $K$, the number of distinct excitement levels possible. On the next\n$K$ lines, output the excitement levels, in increasing order."},{"iden":"note","content":"$1\\le N\\le 2\\cdot 10^5$.\n\n- Inputs 4-8: $N\\le 10$.\n- Inputs 9-20: No additional constraints."}],"translated_statement":null,"sample_group":[["4\nBEEF\n","2\n1\n2\n"],["9\nFEBFEBFEB\n","2\n2\n3"],["10\nBFFFFFEBFE","3\n2\n4\n6"]],"show_order":[],"formal_statement":null,"simple_statement":null,"has_page_source":false}