package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
  a := 0
  b := 1
  return func () int {
    a, b = b, a + b;
    return a;
  }
}

func main() {
  f := fibonacci()
  for i := 0; i < 10; i++ {
    fmt.Println(f())
  }
}