Which of these mountains is not climbed in the National Three Peaks Challenge in the UK?

The National Three Peaks Challenge is an event in which participants attempt to climb the highest mountains of England, Scotland and Wales within 24 hours. It is frequently used to raise money for charitable organizations. Walkers climb each peak in turn and are driven from the foot of one mountain to the next. The three peaks are:

Ben Nevis (1,345 m or 4,413 ft), the highest mountain in Scotland.

Scafell Pike (978 m or 3,209 ft), the highest mountain in England.

Snowdon (1,085 m or 3,560 ft), the highest mountain in Wales.

Helvellyn is a mountain in the English Lake District and is not part of this challenge.

It makes sense to tackle the summits from north to south, starting at Ben Nevis in the evening, and ending at Snowdon the following day. This is because the descent of Ben Nevis is the easiest of the three to do in fading light, particularly the lower section below Lochan Meall an t-Suidhe ("Half-Way Lochan"), and because the night can be used for driving down the A74(M) and M74 motorways to Scafell Pike. This then entails climbing Scafell Pike early the following morning and driving to Snowdonia for the early afternoon, in order to climb Snowdon and descend again by the evening. Scafell Pike can be climbed either from the north side starting at Seathwaite (Borrowdale) or from the south side, starting at Wasdale Head. Snowdon is climbed from Pen-y-Pass, although an alternative descent leads to Llanberis, and takes an additional 15 minutes.