12⁢π⁢ⅈ⁢∫c-ⅈ⁢∞c+ⅈ⁢∞Γ⁡s+a⁢Γ⁡b-s⁢z-s⁢ⅆ⁡s=Γ⁡a+b⁢za1+za+b,