little girl Tanya climb stair inside multistorey building every time Tanya climb stairway start count step 1 number step stairway she speak number aloud for example climb stairway contain 3 step second contain 4 step pronounce number 1 2 3 1 2 3 4you give number pronounce Tanya how stairway climb also output number step stairwayThe give sequence valid sequence Tanya pronounce climbing stairway