Yesterday I got from the aliens strange message. They were flying near Earth and suddenly saw lights. Aliens take off somewhere and near landing hidden treasure from space. By the accident I was near. They gave to me strange manuscript which told coordinates to cache. But how to solve it, I think you and only you may know:
C1C2C3C4C5D4D3E2E1F1F2F3F4F5 G7F7E7D7D6D5E5F5G5G4G3F3E3D3 C7C6C5C4D4E4F4G4F6F5F3F2 B8B7B6B5C5D5F5E7E6E5E4E3 A5B6C7C6C5C4C3. E5F6G7G6G5G4G3 C8D8E8F8F7F6F5F4F3F2E2D2C2C3C4C5C6C7D5E5 C7D7E7E6E5D5C5C6E4E3D3C3
C8D8E8F8C7C6C5D5E5C4C3C2D2E2F2 B6C6D6D5D4D3D2C2B2B3B4B5 C6D7E7F6E5D4C3C2D2E2F2 G7F7E7D7D6D5E5F5G5G4G3F3E3D3 E5F6G7G6G5G4G3 C7D7E7F7F6F5F4E4D4F3F2F1E1D1C1. B6C7D7E6D5C4B3B2C2D2E2 F6G6H6H5H4H3H2G2F2F3F4F5 A5B5C5D5A4A3B3C3D3D2D1C1B1A1