[백준] 2748번 피보나치 수 2 (bronze 1

import java.io.*;
import java.util.*;
public class Main{

    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
        int n=Integer.parseInt(br.readLine());
        long[] num=new long[n+1];
        num[0]=0;
        num[1]=1;
        for(int i=2; i<n+1; i++){
            num[i]=num[i-1]+num[i-2];
        }
        bw.write(num[n]+"");
        bw.flush();
    }
}