The challenge is to climb mere smears of ice on rock, or sometimes, to actually climb rock when no ice is present&#151;using crampons (pointed steel boot attachments) and the front tooth of an ice ax.
(The challenge; is; to climb mere smears of ice on rock, or sometimes) (no ice; is; present)
The challenge no ice
is is
to climb mere smears of ice on rock, or sometimes
present