[쉬움]피보나치

import java.util.ArrayList;

import java.util.List;

import java.util.Scanner;

public class Fibonacci {

/*

public static void main(String[] args){

Scanner in = new Scanner(System.in);

int n = in.nextInt();

int first = 1;

int second = 0;

int temp = 0;

for(int i=1 ; i<n ; i++){

temp = first;

first = first+second;

second = temp;

}

System.out.println(first);

}

*/

public static void main(String[] args){

Scanner in = new Scanner(System.in);

List<Integer> arr = new ArrayList();

arr.add(1);

arr.add(arr.get(0));

int n = in.nextInt();

for(int i=2 ; i<n ; i++){

arr.add(arr.get(i-1)+arr.get(i-2));

}

System.out.println(arr.get(n-1));

}

}