[Gold Ⅴ] 15486 - 퇴사 2

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
public class BOJ_15486 { 
    public static void main(String[] args) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(br.readLine());
        StringTokenizer st;
        int[] day   = new int[N];
        int[] value = new int[N];
        for(int i = 0; i < N; i++){
            st = new StringTokenizer(br.readLine());
            day[i] = Integer.parseInt(st.nextToken());
            value[i] = Integer.parseInt(st.nextToken()); 
        }

        long[] dp = new long[N+1];
        for(int i = N-1; i>= 0; i--){
            int d = day[i];
            int v = value[i];

            if(i+d <= N){
                dp[i] = Math.max(v+dp[i+d], dp[i+1]);
            }else{
                dp[i] = dp[i+1];
            }
        }
        System.out.println(dp[0]);
    }
}