package main
import (
    "fmt"
)
func main(){
    f:=fibonacci()
    for i:=0;i<=20;i++ {
        fmt.Println(f(i))
    }
}
func fibonacci()(func(n int)int){
    var val int
    var val1 int
    return func(n int)int{
        if n==0||n==1{
            val,val1=1,1
        }else{
            val,val1=val+val1,val
        }
        return val
    }
}