In world war 1 the imperial german army developed a piece of artillery called Big Bertha.?

When the barrel was elevated to an angle of 45 degrees, a shell fired from this monstrosity would supposedly travel 72 miles. uming a parabolic trajectory, and neglecting air resistance, curvature of earth, the curvature of Kaiser's moustache, etc. , how maximally far above the earth's surface did the shell get???