Passage: At the age of 17, Steck achieved the 9th difficulty rating (UIAA) in climbing. As an 18-year-old he climbed the North Face of the Eiger and the Bonatti Pillar in the Mont Blanc massif. In June 2004, he and Stephan Siegrist climbed the Eiger, Mönch and Jungfrau within 25 hours. Another success was the so-called "Khumbu-Express Expedition" in 2005, for which the climbing magazine Climb named him one of the three best alpinists in Europe. The project consisted of the first solo climb of the north wall of Cholatse (6,440 m) and the east wall of Taboche (6505 m).Steck set his first speed record on the North Face of the Eiger in 2007, climbing it in 3 hours and 54 minutes. The record was lowered by Steck himself to 2 hours 47 minutes 33 seconds the following year.In May 2008, climbing Annapurna, he broke off his ascent due to an avalanche threat, but the next week climbed to assist Spanish climber Iñaki Ochoa de Olza, who had collapsed. Medical help was slow in coming and the Spanish climber died despite Steck's help.In 2008, Steck was the first recipient of the Eiger Award for his mountaineering achievements.In April 2013, Steck and two other mountaineers, Simone Moro and Jonathan Griffith, were involved in an incident with several Sherpas who were fixing ropes for commercial expeditions on the Lhotse face above camp 2 on the Mount Everest South Col route which subsequently escalated into a dangerous confrontation with many Sherpas after Steck and his companions returned to camp 2, and became an international media event.On 8 and 9 October 2013 Steck soloed the Lafaille route on the South Face of Annapurna. on the main and highest part of the face; this was his third attempt on the route and has been called "one of the most impressive Himalayan climbs in history", with Steck taking 28 hours to make the trip from Base Camp to summit and back again. Steck's was the first solo ascent of Annapurna, which won him his second Piolet d'Or.In the winter of 2014/15, Steck and Michael Wohlleben linked up the three north...

Question: Which walls are consisted in the project's first solo climb?
north wall of Cholatse (6,440 m) and the east wall of Taboche