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 Go (judge verdict: Time Limit Exceeded)

package main

import  (
    "fmt"
    "math"
    )

func main(){
    var n, v, min int
    max := math.MinInt32
    fmt.Scanln(&n)
    fmt.Scanln(&min)
    for i := 1 ; i < n ; i++ {
        fmt.Scanln(&v)
        if max < (v - min) {
            max = (v - min)
        }
        if min > v {
            min = v
        }
    }
    fmt.Println(max)
}