Nice job guys. The key was using the y=x symmetry line.
In the attached
graph, the red and green lines are the two curves. The cyan line y=x is the axis of symmetry. If you subtract the cyan line from the red curve, you get the black curve.
I used
Maxima to find the X-axis intercept of the black curve, and then numerically integrate the black curve from zero to that value and double it.