I have the mathematica code given below. I am using Wolfram Mathematica Online.
 I am very new to Mathematica. When I put this code, I do not get any output. 
It just does not show me anything.




 \[Alpha] = 3;
 F[s_] := Exp[-A*s^(2/\[Alpha])]; integral = 
 Re[Assuming[{A > 0, t > 0, {t, A} \[Element] Reals}, 
 Integrate[F[s]*Exp[s*t] /. s -> I*y, {y, 0, Infinity}]/Pi]]

Can some help me?