package main

import (
	"os"
	"fmt"
	"strconv"
)

func main() {
	input := os.Args[1]
	n, _ := strconv.Atoi(input)
	result := fibonacciDP(n)
	fmt.Println(result)
}

func fibonacci(n int) int {
	if n <= 2 {
		return 1
	}
	return fibonacci(n-1) + fibonacci(n-2)
}

func fibonacciDP(n int) int {
	tmp, n1, n2 := 1, 1, 1
	for i := 1; i < n; i++ {
		tmp = n1 + n2
		n1 = n2
		n2 = tmp
	}
	return tmp
}