Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

Maximum Profit

You can obtain profits from foreign exchange margin transactions. For example, if you buy 1000 dollar at a rate of 100 yen per dollar, and sell them at a rate of 108 yen per dollar, you can obtain (108 - 100) × 1000 = 8000 yen.

Write a program which reads values of a currency $R_t$ at a certain time $t$ ($t = 0, 1, 2, ... n-1$), and reports the maximum value of $R_j - R_i$ where $j > i$ .

Input

The first line contains an integer $n$. In the following $n$ lines, $R_t$ ($t = 0, 1, 2, ... n-1$) are given in order.

Output

Print the maximum value in a line.

Constraints

$2 \leq n \leq 200,000$

$1 \leq R_t \leq 10^9$

Sample Input 1

6
5
3
1
3
4
3

Sample Output 1

3

Sample Input 2

3
4
3
2

Sample Output 2

-1

Solution in JAVA (judge verdict: Accepted)

import java.util.*;
//import java.util.Math.*;

public class Main {
    public static void main(String[] args) throws Exception {

    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int A[] = new int[n];
    int i,j;
    
    for(i = 0; i < n; i++){
        A[i] = sc.nextInt();
       // System.out.println(A[i]);
    }
    
    int min = A[0];
    int maxv = A[1] - A[0];
    
    for(i = 1; i < n; i++){
        if((A[i] - min) > maxv){
            maxv = (A[i] - min);
        }
        if(A[i] < min){
            min = A[i];
        }
    }
    
    System.out.println(maxv);

    }
}