Calculating an Integral by dartboard integration

I'm trying to calculate the integral

and my code is the following

Y=exp(-(pi/2)^2);
A=(pi/2)*Y;
N=100000;
s=0;
for i= 1:N
  x=(pi/2).*rand(1,1);
  y=Y.*rand(1,1);
  if y<=sin(x).*exp(-(x.^2));
      s=s+1;
  end;
end;
I=(A*s)/N

this gives me 0.12 as the result which is wrong it should be about 0.40 I don't know what is wrong with this code thank yo for your help

[Weird Rando]

Sorry I don't know anything about dartboard. But here is what's wrong.

Lets say all the sample fits the if condition (y<=sin(x).*exp(-(x.^2))).
thus your answer is:
I = (A*10000)/10000
A = (pi/2)*Y
Y = exp(-(pi/2)^2)

Hence,
Y = (pi/2)*exp(-(pi/2)^2)
Y = 0.1332

What you should be doing is probably adding all the variable y together and then take the mean of y.