package main

import "fmt"

func fibonacci() func() int {
	previous := 0
	current := 0
	result := 0
	return func() int {
		if current == 0 {
			current = 1
		} else if current == 1 && result == 0 {
			result = current
		} else {
			result = previous + current
			previous = current
			current = result
		}
		return result
	}
}

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