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$\int_0^1 \mathrm{~d} x \int_0^x \sqrt{1+y^2} \mathrm{~d} y+3 \int_0^1 \mathrm{~d} y \int_1^{\sqrt{2-y^2}} \sqrt{x^2+y^2} \mathrm{~d} x=$
                        
不再提醒