Problem:
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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 C (judge verdict: Time Limit Exceeded)

#include <stdio.h>
#include <stdlib.h>
int main( ) {
    int t;
    int readnumber = scanf("%d", &t);
    if(t<2||t>200000)
        return 0;
    
    int arrayR[t];
    for(int i=0; i< t; i++)
    {
        int readArray = scanf("%d", &arrayR[i]);
    }
    
    int l = (t)*(t-1)/2;
    int a,b,c;
    int max = arrayR[1]-arrayR[0];
    for(int j=t-1; j>=0; j--)
    {
        for(int i= j-1; i>=0; i-- )
        {
            a = arrayR[j] - arrayR[i]; 
            if(max < a)
            max = a;
        }
    }
    printf("%d\n", max);
    return (EXIT_SUCCESS);
}