100% Absolute proof of flat earth

Earth curvature formula : 8 inches per mile squared 
the mountain we can see is at 263 km.
263 km to miles = 163 miles
163² = 26569 * 8 (inches) = 212552 inches = 5400 meters

The canigou mountain is 2786 meters high, 

This mountain shouldn't be visible hidden by more than 2600 meters of curvature... 

Now tell me that it's light bending !