flowchart TD A[Start] --> B{Is it?}; B -- Yes --> C[OK]; C --> D[Rethink]; D --> B; B -- No ----> E[End];

sequenceDiagram Alice->>+John: Hello John, how are you? Alice->>+John: John, can you hear me? John-->>-Alice: Hi Alice, I can hear you! John-->>-Alice: I feel great!