I have 138 wagons

So there are numerous options

Option 1: 1 Legendary Black + 1 Epic Black
CP: 62,500 + 12,500 = 75,000
Add 1 Rare Black (2,500) × 14 = 35,000
Total CP = 110,000
Add 1 Common Gold (125) × 9 = 1,125
Total CP = 111,125 (very close)
Total cards = 1 + 1 + 14 + 9 = 25 cards
So, 690 ÷ 25 = 27 full sets → 27 × 111,125 ≈ 3,000,375 CP

This is co-pilot as you can tell, and obviously I won't do it this way