model
 {
  for(i in 1:n1){
   y[i] ~ dexp(theta1)
  }
  for(i in 1:n2){
   x[i] ~ dexp(theta2)
  }
  theta1 ~ dgamma(0.01,0.01)
  theta2 ~ dgamma(0.01,0.01)
  median1 <- log(2)/theta1
  median2 <- log(2)/theta2
 }